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97 Cards in this Set
- Front
- Back
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Why does soda fizz?
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Soda fizzes due to the interactions between carbon dioxide and water under high pressure. At room temperature, carbon dioxide is a gas and water is a liquid. Through the use of pressure, the makers of soda force the carbon dioxide gas to dissolve in the water. When the can is sealed, the solution remains mixed. When the can is opened, the pressure is released and the carbon dioxide molecules escape in bubbles of gas.
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What do chemists try to do? How do they understand
the natural world? |
Chemists study molecules and interactions at the molecular level to learn about and explain macroscopic events. Chemists attempt to explain why ordinary things are as they are.
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Define chemistry.
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Chemistry is the science that seeks to understand what matter does by studying what atoms and molecules do.
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Explain the scientific method.
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The scientific method is the way chemists investigate the chemical world. The first step consists of observing the natural world. Later observations can be combined to create a scientific law, which summarizes and predicts behavior. Theories are models that strive to explain the cause of the observed phenomenon. Theories are tested through experiment. When a theory is not well established, it is sometimes referred to as a hypothesis.
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What is the difference between a law and a theory?
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A law is simply a general statement that summarizes and predicts observed behavior. Theories seek to explain the causes of observed behavior.
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What is wrong with the statement, “It is just a
theory”? |
To say “It is just a theory” makes it seem as if theories are easily discardable. However, many theories are very well established and are as close to truth as we get in science. Established theories are backed up with years of experimental evidence, and they are the pinnacle of scientific understanding.
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What is the atomic theory, and who formulated it?
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The atomic theory states that all matter is composed of small, indestructible particles called atoms. John Dalton formulated this theory.
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Classify each statement as an observation, a law, or a
theory. (a) When a metal is burned in a closed container, the sum of the masses of the container and its contents do not change. (b) Matter is made of atoms. (c) Matter is conserved in chemical reactions. (d) When wood is burned in a closed container, its mass does not change. |
a. observation
b. theory c. law d. observation |
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Why is it important to report units with scientific
measurements? |
Without units, the results are unclear and it is hard to keep track of what each separate measurement entails.
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Why is scientific notation useful?
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Often scientists work with very large or very small numbers that contain a lot of zeros. Scientific notation allows these numbers to be written more compactly, and the information is more organized.
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Explain when zeros count as significant digits and
when they do not. |
Zeros count as significant digits when they are interior zeros (zeros between two numbers) and when they are trailing zeros (zeros after a decimal point). Zeros are not significant digits when they are leading zeros, which are zeros to the left of the first nonzero number.
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What limits the number of significant digits in a calculation involving only multiplication and division?
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For calculations involving only multiplication and division, the result carries the same number of significant figures as the factor with the fewest significant figures.
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How are significant figures determined in calculations involving both addition/subtraction and multiplication/ division?
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In calculations involving both multiplication/division and addition/subtraction, do the steps in parentheses first; determine the correct number of significant figures in the intermediate answer; then do the remaining steps.
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What are the basic SI units of length, mass, and time?
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The basic SI unit of length is the meter. The kilogram is the SI unit of mass. Lastly, the second is the SI unit of time.
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Suppose you are trying to measure the diameter of a Frisbee. What unit and prefix multiplier should you use?
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For measuring a Frisbee, the unit would be the meter and the prefix multiplier would be centi-. The final measurement would be in centimeters.
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Explain why units are important in calculations.
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Units act as a guide in the calculation and are able to show if the calculation is off track. The units must be followed in the calculation, so that the answer is correctly written and understood.
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What is a conversion factor?
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A conversion factor is a quantity used to relate two separate units. They are constructed from any two quantities known to be equivalent.
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Write the conversion factor that converts a measurement in inches to feet. How would the conversion factor change for converting a measurement in feet to inches?
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The conversion factor is 1ft / 12in . For a feet-to-inches conversion, the conversion factor must be inverted to 12in / 1ft.
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This book outlines a four-step problem-solving strategy. Describe each step and its significance.
(a) Sort (b) Strategize (c) Solve (d) Check |
a. Sort the information into the given information (the starting point for the problem) and the find information (the end point).
b. Create a solution map to get from the given information to the information you are trying to find. This will likely include conversion factors or equations. c. Follow the solution map to solve the problem. Carry out mathematical operations and cancel units as needed. d. Ask, does this answer make physical sense? Are the units correct? Is the number of significant figures correct? |
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What is density? Explain why density can work as a
conversion factor. Between what quantities does it convert? |
The density of a substance is the ratio of its mass to its volume. Density is a fundamental property of materials and differs from one substance to another. Density can be used to relate two separate units, thus working as a conversion factor. Density is a conversion factor between mass and volume.
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How many significant figures are in each measured
quantity? (a) 0.001125 m (b) 0.1125 m (c) 1.12500 * 10^4 m (d) 11205 m |
a. 4
b. 4 c. 6 d. 5 |
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Define matter and list some examples.
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Matter is defined as anything that occupies space and possesses mass. It can be thought of as the physical material that makes up the universe.
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What are the three states of matter?
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The three states of matter are solid, liquid, and gas.
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What is the difference between a crystalline solid and an amorphous solid?
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In a crystalline solid, the atoms/molecules are arranged in geometric patterns with repeating order. In amorphous solids, the atoms/molecules do not have long-range order.
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What are the properties of a gas?
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The atoms/molecules in gases are not in contact with each other and are free to move relative to one another. The spacing between separate atoms/molecules is very far apart. A gas has no fixed volume or shape; rather, it assumes both the shape and the volume of the container it occupies.
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What is a mixture?
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A mixture is two or more pure substances combined in variable proportions.
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What is a pure substance?
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Pure substances are those composed of only one type of atom or molecule.
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What is the difference between a mixture and a compound?
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A mixture is formed when two or more pure substances are mixed together; however, a new substance is not formed. A compound is formed when two or more elements are bonded together and form a new substance.
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What is the difference between a physical change and
a chemical change? |
In a physical change, the composition of the substance does not change, even though its appearance might change. However, in a chemical change, the substance undergoes a change in its composition.
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What is the definition of energy?
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Energy is defined as the capacity to do work.
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Explain the difference between kinetic energy and
potential energy. |
Kinetic energy is the energy associated with the motion of an object. Potential energy is the energy associated with the position or composition of an object.
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What are three common units for energy?
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Three common units for energy are joules, calories, and kilowatt-hour.
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What is an endothermic reaction? Which has greater energy in an endothermic reaction, the reactants or the products?
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An endothermic reaction is one that absorbs energy from the surroundings. The products have more energy than the reactants in an endothermic reaction.
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Explain the difference between heat and temperature.
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Heat is the transfer of thermal energy caused by a temperature difference, whereas temperature is a measure of the thermal energy of matter.
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What is heat capacity?
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Heat capacity is the quantity of heat energy required to change the temperature of a given amount of the substance by 1 °C.
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Classify each pure substance as an element or a
compound. (a) aluminum (b) sulfur (c) methane (d) aceton |
a. element
b. element c. compound d. compound |
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Classify each mixture as homogeneous or heterogeneous.
(a) coffee (b) chocolate sundae (c) apple juice (d) gasoline |
a. homogeneous
b. heterogeneous c. homogeneous d. homogeneous |
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Classify each substance as a pure substance or a mixture.
If it is a pure substance, classify it as an element or a compound. If it is a mixture, classify it as homogeneous or heterogeneous. (a) helium gas (b) clean air (c) rocky road ice cream (d) concrete |
a. pure substance-element
b. mixture-homogeneous c. mixture-heterogeneous d. mixture-heterogeneous |
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Classify each property as physical or chemical.
(a) the tendency of silver to tarnish (b) the shine of chrome (c) the color of gold (d) the flammability of propane gas |
a. chemical
b. physical c. physical d. chemical |
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The following list contains several properties of ethylene (a ripening agent for bananas). Which are physical properties, and which are chemical?
• colorless • odorless • flammable • gas at room temperature • 1 L has a mass of 1.260 g under standard conditions • mixes with acetone • polymerizes to form polyethylene |
physical–colorless; odorless; gas at room temperature; one liter has a mass of 1.260 g under standard conditions; mixes with acetone; chemical–flammable; polymerizes to form polyethylene
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Determine whether each change is physical or chemical.
(a) A balloon filled with hydrogen gas explodes upon contact with a spark. (b) The liquid propane in a barbecue evaporates away because the user left the valve open. (c) The liquid propane in a barbecue ignites upon contact with a spark. (d) Copper metal turns green on exposure to air and water. |
a. chemical
b. physical c. chemical d. chemical |
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A block of aluminum is (a) ground into aluminum powder and then (b) ignited. It then emits flames and smoke. Classify (a) and (b) as chemical or physical changes.
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a. physical
b. chemical |
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An automobile gasoline tank holds 42 kg of gasoline. When the gasoline burns, 168 kg of oxygen are consumed and carbon dioxide and water are produced. What is the total combined mass of carbon dioxide and water that is produced?
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2.10 * 10^2 kg
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Are these data sets on chemical changes consistent with the law of conservation of mass? (a) A 7.5-g sample of hydrogen gas completely reacts with 60.0 g of oxygen gas to form 67.5 g of water. (b) A 60.5-g sample of gasoline completely reacts with 243 g of oxygen to form 206 g of carbon dioxide and 88 g of water.
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a. Yes
b. No |
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In a butane lighter, 9.7 g of butane combine with 34.7 g of oxygen to form 29.3 g carbon dioxide and how many grams of water?
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15.1 g of water
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Determine whether each process is exothermic or
endothermic. (a) gasoline burning in a car (b) isopropyl alcohol evaporating from skin (c) water condensing as dew during the night |
a. exothermic (loses heat),
b. endothermic (gains heat), c. exothermic (loses heat) |
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What did Democritus contribute to our modern understanding of matter?
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Democritus theorized that matter was ultimately composed of small, indivisible particles called atoms. Upon dividing matter, one would find tiny, indestructible atoms.
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Describe Rutherford’s gold foil experiment and the results of that experiment. How did these results contradict the plum pudding model of the atom?
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Rutherford’s gold foil experiment involved sending positively charged alpha-particles through a thin sheet of gold foil and detecting if there was any deflection of the particles. He found that most passed straight through, yet some particles showed some deflection. This result contradicts the plum-pudding model of the atom because the plum-pudding model does not explain the deflection of the alpha-particles.
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List the three subatomic particles and their properties.
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Proton: mass = 1amu, Charge +1
Neutron: mass = 1amu, Charge 0 Electron: mass = 0.00055amu, Charge -1 |
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Is matter usually charge-neutral? How would matter be different if it were not charge-neutral?
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Matter is usually charge-neutral due to protons and electrons having opposite charges. If matter were not charge neutral, many unnatural things would occur, such as objects repelling or attracting each other.
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What is a chemical symbol?
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A chemical symbol is a unique one- or two-letter abbreviation for an element. It is listed below the atomic number for that element on the periodic table.
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What was Dmitri Mendeleev’s main contribution to our modern understanding of chemistry?
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Mendeleev noticed that many patterns were evident when elements were organized by increasing mass; from this observation he formulated the periodic law. He also organized the elements based on this law and created the basis for the periodic table being used today.
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How is the periodic table organized?
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The periodic table is organized by listing the elements in order of increasing atomic number.
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What are the properties of nonmetals? Where are nonmetals found on the periodic table?
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Nonmetals have varied properties (solid, liquid, or gas at room temperature); however, as a whole they tend to be poor conductors of heat and electricity, and they all tend to gain electrons when they undergo chemical changes. They are located toward the upper right side of the periodic table.
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What is a family or group of elements?
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Each column within the main group elements in the periodic table is labeled as a family or group of elements. The elements within a group usually have similar chemical properties.
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What is an ion?
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An ion is an atom or group of atoms that has lost or
gained electrons and has become charged. |
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Locate each group on the periodic table and list the
charge of the ions it tends to form. (a) Group 1A (b) Group 2A (c) Group 3A (d) Group 6A (e) Group 7A |
a) +1
b) +2 c) +3 d) -2 e) -1 |
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What is the percent natural abundance of isotopes?
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The percent natural abundance of isotopes is the relative amount of each different isotope in a naturally occurring sample of a given element.
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What notations are commonly used to specify
isotopes? What do each of the numbers in these symbols mean? |
Isotopes are noted in this manner: A/Z X
X represents the chemical symbol, A represents the mass number, and Z represents the atomic number. |
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Which statements are inconsistent with Dalton’s atomic theory as it was originally stated? Why? (a) All carbon atoms are identical. (b) Helium atoms can be split into two hydrogen atoms. (c) An oxygen atom combines with 1.5 hydrogen atoms to form water molecules. (d) Two oxygen atoms combine with a carbon atom to form carbon dioxide molecules.
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a. Correct.
b. False; different elements contain different types of atoms according to Dalton. c. False; one cannot have 1.5 hydrogen atoms; combinations must be in simple, whole-number ratios. d. Correct. |
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Which statements are inconsistent with Rutherford’s nuclear theory as it was originally stated? Why? (a) Helium atoms have two protons in the nucleus and two electrons outside the nucleus. (b) Most of the volume of hydrogen atoms is due to the nucleus. (c) Aluminum atoms have 13 protons in the nucleus and 22 electrons outside the nucleus. (d) The majority of the mass of nitrogen atoms is due to their 7 electrons.
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a. Correct.
b. False; most of the volume of the atom is empty space occupied by tiny, negatively charged electrons. c. False, the number of negatively charged particles outside the nucleus equals the number of positively charged particles inside the nucleus. d. False, the majority of the mass of an atom is found in the nucleus. |
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If atoms are mostly empty space, and atoms compose all ordinary matter, then why does solid matter seem to have no space within it?
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Solid matter seems to have no empty space within it because electromagnetic forces hold the atoms in a tight arrangement and the variation in density is too small to perceive with our eyes.
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Which statements about electrons are true?
(a) Electrons repel each other. (b) Electrons are attracted to protons. (c) Some electrons have a charge of and some have no charge. (d) Electrons are much lighter than neutrons. |
a, b, d
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Which statements about protons are true?
(a) Protons have twice the mass of neutrons. (b) Protons have the same magnitude of charge as electrons but are opposite in sign. (c) Most atoms have more protons than electrons. (d) Protons have a charge of 1+. |
b, d
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How many electrons would it take to equal the mass
of a proton? |
1.8 x 10^3 electrons
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What mass of electrons would be required to just
neutralize the charge of 1.0 g of protons? |
5.4 x 10^-4 g
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Find the atomic number (Z) for each element.
(a) Fr (b) Kr (c) Pa (d) Ge (e) Al |
a) 87
b) 36 c) 91 d) 32 e) 13 |
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How many protons are in the nucleus of an atom of
each element? (a) Ar (b) Sn (c) Xe (d) O (e) Tl |
a) 18
b) 50 c) 54 d) 8 3) 81 |
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List the symbol and atomic number corresponding to
each element. (a) carbon (b) nitrogen (c) sodium (d) potassium (e) copper |
a) C, 6
b) N, 7 c) Na, 11 d) K, 19 e) Cu, 29 |
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List the name and the atomic number corresponding
to the symbol for each element. (a) Mn (b) Ag (c) Au (d) Pb (e) S |
a. manganese, 25
b. silver, 47 c. gold, 79 d. lead, 82 e. sulfur, 16 |
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Classify each element as a metal, nonmetal, or
metalloid. (a) Sr (b) Mg (c) F (d) N (e) As |
a) metal
b) metal c) nonmetal d) nonmetal e) metalloid |
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Which elements would you expect to lose electrons
in chemical changes? (a) potassium (b) sulfur (c) fluorine (d) barium (e) copper |
a, d, e
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Which elements are main-group elements?
(a) Te (b) K (c) V (d) Re (e) Ag |
a, b
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Which elements are alkaline earth metals?
(a) sodium (b) aluminum (c) calcium (d) barium (e) lithium |
c, d
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Which elements are alkali metals?
(a) barium (b) sodium (c) gold (d) tin (e) rubidium |
b, e
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Classify each element as a halogen, a noble gas, or
neither. (a) Cl (b) Kr (c) F (d) Ga (e) He |
a) halogen
b) noble gas c) halogen d) neither e) noble gas |
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To what group number does each element belong?
(a) oxygen (b) aluminum (c) silicon (d) tin (e) phosphorus |
a) 6A
b) 3A c) 4A d) 4A e) 5A |
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Which element do you expect to be most like sulfur?
Why? (a) nitrogen (b) oxygen (c) fluorine (d) lithium (e) potassium |
b, oxygen; it is in the same group or family
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Which pair of elements do you expect to be most
similar? Why? (a) Si and P (b) Cl and F (c) Na and Mg (d) Mo and Sn (e) N and Ni |
b, chlorine and fluorine; they are in the same family or group
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Determine the charge of each ion.
(a) oxygen ion with 10 electrons (b) aluminum ion with 10 electrons (c) titanium ion with 18 electrons (d) iodine ion with 54 electrons |
a) 2-
b) 3+ c) 4+ d) 1- |
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Determine the number of protons and electrons in each ion.
(a) Na+ (b) Ba2+ (c) O2+ (d) Co3+ |
a. 11 protons, 10 electrons
b. 56 protons, 54 electrons c. 8 protons, 10 electrons d. 27 protons, 24 electrons |
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Predict the ion formed by each element:
(a) Rb (b) K (c) Al (d) O |
a) Rb+
b) K+ c) Al^3+ d) O^2- |
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Predict how many electrons will most likely be
gained or lost by each element: (a) Ga (b) Li (c) Br (d) S |
a) 3 electrons lost
b) 1 electron lost c) 1 electron gained d) 2 electrons gained |
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What are the atomic number and mass number for
each isotope? (a) the hydrogen isotope with 2 neutrons (b) the chromium isotope with 28 neutrons (c) the calcium isotope with 22 neutrons (d) the tantalum isotope with 109 neutrons |
a) Z=1, A=3
b) Z=24, A=52 c) Z=20, A=42 d) Z=73, A=182 |
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Do the properties of an element change when it combines with another element to form a compound? Explain.
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Yes; when elements combine with other elements, a compound is created. Each compound is unique and contains properties different from those of the elements that compose it.
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What is the law of constant composition? Who
discovered it? |
The law of constant composition states that all samples of a given compound have the same proportions of their constituent elements. Joseph Proust formulated this law.
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In a chemical formula, which element is listed first?
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The more metallic element is generally listed first in a
chemical formula. |
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Explain the difference between a molecular formula
and an empirical formula. |
The empirical formula gives the relative number of atoms of each element in a compound. The molecular formula gives the actual number of atoms of each element in a molecule of the compound.
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What is the difference between a molecular element and an atomic element? List the elements that occur as diatomic molecules.
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An atomic element is one that exists in nature with a single atom as the basic unit. Amolecular element is one that exists as a diatomic molecule as the basic unit. Molecular elements include H2, N2, O2, F2, Cl2, Br2, I2
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What is the difference between a common name for a compound and a systematic name?
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The systematic name can be directly derived by looking at the compound’s formula. The common name for a compound acts like a nickname and can only be learned through familiarity.
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Find the block in the periodic table of metals that tend to form more than one type of ion. What is the name of this block?
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The block that contains the elements for Type II compounds is known as the transition metals.
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What is the basic form for the names of ionic compounds containing a metal that forms more than one type of ion?
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The basic form for the names of Type II ionic compounds is to have the name of the metal cation first, followed by the charge of the metal cation (in parentheses, using Roman numerals), and finally the base name of the nonmetal anion with -ide attached to the end.
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How are compounds containing a polyatomic ion named?
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For compounds containing a polyatomic anion, the name of the cation is first, followed by the name for the polyatomic anion. Also, if the compound contains both a polyatomic cation and a polyatomic anion, one would just use the names of both polyatomic ions.
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What is the basic form for the names of molecular compounds?
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The form for naming molecular compounds is to have the first element preceded by a prefix to indicate the number of atoms present. This is then followed by the second element with its corresponding prefix and -ide placed on the end of the second element.
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What is the basic form for the names of binary acids?
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To correctly name a binary acid, one must begin the first word with hydro-, which is followed by the base name of the nonmetal plus -ic added on the end. Finally, the word acid follows the first word.
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What is the basic form for the name of oxyacids
whose oxyanions end with -ite? |
To name an acid with oxyanions ending with -ite, one must take the base name of the oxyanion and attach -ous to it; the word acid follows this.
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Classify each element as atomic or molecular.
(a) chlorine (b) argon (c) cobalt (d) hydrogen |
a) molecular
b) atomic c) atomic d) molecular |
