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113 Cards in this Set
- Front
- Back
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The mass that enters into a chemical reaction remains unchanged.
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Boyle's law
The law of conservation of mass |
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Mass is neither created nor destroyed in a chemical reaction.
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The law of conservation of mass
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The elements that compose a compound are present in fixed and precise proportion by mass.
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The law of constant composition.
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When the same elements can form 2 different compounds, the ratio of masses of one of the elements in the 2 compounds is a small whole number relative to the given mass of the other element.
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The law of multiple proportions
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States that all atoms of an element were identical and they have the same mass.
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Dalton's atomic theory
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states elements consisted of tiny particles called atoms. Compounds consisted of atoms of different elements combined together. Chemical reactions involved the rearrangement of combinations of those atoms.
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Atomic Theory
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a tabular representation of all the elements arranged according to their atomic number (the number of protons in their nucleus) and their chemical properties
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The periodic table
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The mass of an atom is...
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the sum of its protons and neutrons.
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What is an isotope?
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The number of protons for a given element is fixed, but the number of neutrons may vary.
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Where is the atomic number found? the atomic mass?
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The atomic number is on the top of the element listed on the periodic table. The atomic mass is found under the element.
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What determines the atomic mass?
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based on the sum of protons & neutrons
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Isotopes change the ______ but not the _______.
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atomic weight; atomic number
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In the periodic table, columns of elements have what in common?
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They are elements with similar numbers and characteristics of electrons in the outer orbitals and therefore, similar chemical properties.
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The chemical properties of an element are related to what?
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Chemical properties are related to the number and characteristics of the electrons in theoutermost (most energetic) orbitals-valence electrons
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The number of electrons is the same as what?
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the number of protons (the atomic number)
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On the periodic table, what structures are the most stable and why?
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noble gases are the most stable because they have 8 valence electrons in the outer shell
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On the periodic table what changes in a row when you go from left to right?
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When you go from left to right on a particular row, the number of valence electrons increases by 1.
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What are valence electrons? what is their significance?
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electrons that are in the outermost shell. they determine the chemical behavior of an atom
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Atomic size is determined by...
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how much space the elecrons take up.
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Ionization energy is ...
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the energy required to remove the outermost electron from an atom.
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ability of an atom to attract electrons.
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electronegativity
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results from sharing one or more electron pairs between two atoms
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covalent bonding
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results from electrostatic attractions among ions, which are formed by the transfer of one or more electrons from one atom to another.
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ionic bonding
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nonmetal to nonmetal bonding
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covalent bond
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consists of two or more atoms held together by covalent bonds
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molecule
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the sharing of one pair of valence electrons
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single bond
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the sharing of two pairs of valence electrons
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double bond
double bonds put rotation restrictions on molecules |
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The more bonds the more energy required to break them apart. T/F
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True
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The more _____ an atom the stronger it pulls shared electrons toward itself.
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electronegative
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electronegativity _____ from left to right across the periodic table.
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increases
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The type of bond that shares the electron equally and the atoms have similar electronegativities.
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nonpolar covalent bond
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The type of bond that share the electrons unequally and the atoms have differing electronegativities.
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polar covalent bond
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An anion is ...
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negatively charged (aquired an electron)
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A cation is ...
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positively charged (gave up an electron)
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What are ions?
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Charged atoms with more or fewer electrons than usual.
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an attraction between anions and cations
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ionic bond
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metal bonded with nonmetal
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ionic bond
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ionic compounds are often called what?
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salts
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In a solution, each ion is surrounded by ?
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water molecules
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Negatively charged polyatomic ions have ____ electrons in their covalent bonds than they do protons in all their collective nuclei.
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more
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Positively charged polyatomic ions have ____ electrons in their covalent bonds than protons in all their collective nuclei.
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fewer
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Polyatomic ions associate with _______ to produce electrical neutrality in the compound.
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ions of the opposite charge
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The ____ of the molecule is very important to its function in the living cell and is determined by the positions of its atoms valence orbitals.
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shape
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determines how biological molecles, recognize and respond to one another with specificity.
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Molecular shape
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statement of the ratios of elements that make up a compound.
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formula
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Formula weight is ...
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the sum of the atomic weights of the constituent atoms of the formula.
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In ___ compounds, the ratio may reflect the actual composition of a molecule.
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covalent
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In ___ compounds, it is the ratio of ions that make up the compound.
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ionic
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A mole =
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6.022 x 10exp23
Avagadro's number |
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mass in grams numberically equal to the atomic weight of the element in grams
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molar mass
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1 M solution is...
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the concentration of one mole of a compound in 1 liter of solution.
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1 M solution could also be 1/10 the formula weight dissolved in
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100 ml of solution
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Mixtures in which the solvent and solute are intimately associated as molecules or ions
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Solutions
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Solutions in which the solvent is water
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Aqueous solutions
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Solutes in aqueous solutions can be ...
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gases, other liquids, or solids.
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Water molecules are...
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polar
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Solutes that can interact with the positive or negative (or both) ends of the ater molecule will be...
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soluble in water.
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Substances that are easily soluble in water
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hydrophilic
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Substances that are poorly soluble in water
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hydrophobic
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Hydrophilic/soluble substances are usually...
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polar
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Hydrophobic/insoluable substances are usually...
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nonpolar (no charge)
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Solids that dissolve in water are ____ soluble the higher the temperature of the water.
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more
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Liquids that dissolve in water are...
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miscible
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Liquids that don't dissolve in water are...
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immiscible
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Gases dissolve in water because ....
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they exert pressure on the surface of the water.
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Gases dissolve in water according to their...
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partial pressure in the atmosphere above/in contact with the water.
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O2 is _____ soluble in water.
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not very
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CO2 is ____ soluble in water.
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very
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property that enables substances to become evenly distributed in a solution.
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Diffusion
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All molecules, ions, and atoms possess ....
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thermal energy (at temperatures above absolute zero).
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Atoms/molecules/ions in a _______ or in solution are free to move in a straight line until they collide with something.
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liquid or gaseous state
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Atoms/molecules/ions in a ____ are held in place by strong attractive forces and just vibrate because of their thermal energy.
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solid
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Substances always diffuse ...
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down their concentration gradient (from more concentrated areas to less concentrated areas until all areas have equal concentration)
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At equal concentration, _____ movement occurs.
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no net movement, although individual atoms/molecules/ions are still moving about as they did before.
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basically diffusion that occurs across a semipermeable membrane
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Osmosis
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The molecules leaving a given area are balanced by the ones arriving in that area. T/F
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true. remain in a state of equillibrium
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Membrane that will let some of the components of the solution cross but will exclude others.
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semipermeable membrane
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Most membranes are freely permeable to
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water.
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lipid membranes that are impermeable to charged molecules
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cell membranes
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Biological membranes are made of lipids, so most ______ cannot cross.
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charged substances, such as ions and polar molecules
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If there are concentration differences across biological membranes, _____ must cross the membranes to equalize them.
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water
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The propensity of water to cross a semipermeable membrane to equalize solute concentrations on either side
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osmotic pressure
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energy supplying reaction
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exothermic (reactants are at a higher energy level than the product-energy is produced)
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energy requiring reaction
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endothermic (energy must be introduced to get the reaction started)
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Increasing the concentration of the reactants_____ the reaction.
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speeds up
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Increasing the temperature ____ the reaction.
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speeds up
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speed up reactions by lowering the activation energy
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catalysts
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Catalysts ____ entropy, which is a measure of _______ that contributes to the activation energy.
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reduce; randomness
catalysts speed up reactions by making productive collisions between the reactants more likely |
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Catalysts are usually...
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protein molecules called enzymes.
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Enzymes reduce the _____ by reducing the ______.
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activation energy; entropy
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Many chemical reactions are ...
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reversible-they go forward or backward.
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Reversible reactions can go completely forward or completely backward. T/F
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False. Reactions will never go completely forward or completely backward.
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Reversible reactions have an ______ between the forward and the backward reaction.
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equillibrium
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States any change in status quo prompts an opposing reaction in the responding system.
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The Principle of LeChatelier
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When the concentration of one of the reactants is increased, the reaction is pushed toward the
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right
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When the concentration of one of the products is increased, the reaction is pushed to the
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left
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Some isotopes of elements with atomic numbers less than or equal to 83 and all elements with atomic numbers greater than 83 are...
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radioactive
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Isotopes that have nuclei that are unstable and emit energy in the form of particles or electromagnetic waves
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radioactive
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2 protons and 2 neutrons (a helium nucleus) emitted as a group
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alpha particle
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electron that comes from the nucleus
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beta particle
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a high energy electromagnetic wave, of higher energy than x-rays
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gamma ray
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particle the size of an electron but with a positive charge
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positron
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When alpha or beta particles are emitted what happens?
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the nucleus changes its atomic number (number of protons) and hence becomes another element
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Radioactive elements decay according to a ____ which is different for each element and isotope.
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half life
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Isotopes in nuclear medicine, have ____ half lives.
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extremely short; good to have a short life for radioactive isotopes because after the scan is done, the radioactivity rapidly disappears
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Isotopes used in radiation medicine have ____ half lives.
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longer; days, weeks, or in some instances, years
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Patients given a radioactive isotope by IV will have radioactive excreta. T/F
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True; must be handled per protocol
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If the patient has a radioactive implant, their excreta will be radioactive. T/F
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False. The excreta is not radioactive because it is confined by the sealed implant.
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Radioactivity produces ____ of chemicals that it hits.
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ionization
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In the case of human exposure, the most damaging ionization occurs in ...
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the person's DNA.
Ionizing radiation can produce so much DNA damage that the cell dies. This is the purpose of ionizing radiation directed at tumors. |
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Ionizing radiation may produce smaller amounts of DNA damage that survive as ...
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permanent mutations.
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Mutations may combine with other mutations in the same cell to produce
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malignant transformation
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Patients who have received radiation to treat one cancer have increased their chances of what?
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increased incidence of second malignancy in the area that they received radiation
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