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86 Cards in this Set
- Front
- Back
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Hypothesis
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Statement or question that can be tested
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Hypothesis statement:
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Strength is proportional to the amount of training an athlete does
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Hypothesis question:
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Is strength proportional to athletic training?
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Experiment
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Tests the hypothesis
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Independent Variable
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input variable- how many minitues a day each of the 4 groups train at the gym lifting weights each day
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Dependent Variable
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Output variable- the number of pounds each person can bench press in each group
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Validity
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measuring the quantity or quality that it is supposed to measure
ie: Measuring a patients temp to check for infection; since infections usually come with temperatures it is NOT valid to measure back pain |
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Reliability
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Ability to repeat over and over again
A scale that weighs patients 8 pounds under is Reliable but not valid. you can repeat it over and over again (reliability) but it is NOT measuring what it is supposed to (Validity) If only a couple of times gets right weight, it is slightly valid, and not reliable |
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Scientific notation
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Powers of 10
10^0 = 1 10^1 = 10 10^2 = 100 10^3 = 1000 10^4 = 10,000 10^5 = 100,000 10^-1 = 0.1 10^-2 = 0.01 10^-3 = 0.001 10^-4 = 0.0001 10^-5 = 0.00001 *** JUST MOVE THE DECIMAL R or L the # of spots in the exponent |
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Scientific notation calculations of multiple numbers:
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For calculation, multiply or divide the conventional numbers separately; then add or subtract the powers of 10:
ie: 4.16 x 10^5 x 3.1 x 10^-3 = (4.16 x 3.1) x (10^5 x 10^-3)= (12.896) x (10^5 +^-3) = 12.896 x 10^2= 1289.6 OR 20.5 x 10^3 / 4.1 x 10^-3 = (20.5 / 4.1) x (10^5 x 10^-3) (5.0) x (10^3 - ^-3) 5.0 x 10^6 5,000,000 |
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A hospital manager suspects that the pay scale for nurses and the number of complaints that the hospital receives from patients are inversely proportional. The manager is organizing a stidy to prove her hypothesis. Which of the following would be the dependent variable for the study?
A) # of nurses B) # of complaints C) Pay scale for nurses D) # of patients |
The input, or independent variable, in this study is the pay scales that are given to the nurses
The output, or dependent variable, will emerge with each different level of pay, making: B) Number of complaints |
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Which is greater: 0.055 x 10^5
OR 5 x 10^-1 / 9 x 10^-3 |
1st: 0.055 = 550
2nd = (5/9) x (10^-1^-3) = .55 x 10^2 = 5.5 x 10^1 = 55 A is correct |
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Which of the following measurements is reliable but not valid?
A) Patient making a self-diagnosis B) 4 doctors coming up with 4 defferent diagnosis C) 4 docs agree on wrong diagnosis D) 4 Docs disagreeing about patients diagnosis |
C) 4 docs agree on wrong diagnosis
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Element
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pure substance that cannot be broken down into different substances
Composed of a single kind of atom with a particular form, mass, and structure |
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Is table salt an element?
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no it breaks down into sodium metal and chlorine gas when electricity ran thru it
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Is sodium and chlorine elements?
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Yes, cannot be separated
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Composition of a atom:
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protons
neutrons electrons |
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Protons
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Positively charged
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Neutrons
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Neutral
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Electrons
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Negative
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Protons and neutrons are located:
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central nucleus
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Electrons (-) located:
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surrounding the nucleus
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Atomic #
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How many protons and electrons an element has (usually top left corner)
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Atomic mass:
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Measured in amu (atomic mass units)
Measure for how many Protons + Neutrons (electrons are - and have hardly no mass) Na+ atomic mass is 11 protons + 12 Neutrons = 23 amu |
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Compound
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pure substance composed of 2 or more atoms that are bonded together.
Composed of molecules |
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How many neutrons does the element phosphorus have?
A) 15 B) 16 C) 31 D) 46 |
Answer: atomic # + atomic mass = n
31=15 +n n+ 16 B) 16 |
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Is gydrogen gas, H2, an element or compound?
A) H2 is a compound because it has 2 atoms B) H2 is an element because it has 2 atoms C) H2 is an element because it has only 1 kind of atom D) H2 is an element because it has two kinds of atoms |
A compound is defined as being composed of molecules having more than one kind of atom. H2 has only one kind of atom, hydrogen, that is bonded to itself, so H2 cannot be a compound.
An element is defined as having only 1 kind of atom, making (C) the correct answer C) H2 is an element because it has only 1 kind of atom |
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Atomic Radius
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Distance from the Nucleus to the outer most electron
Decreases left to right |
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Ionization energy
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energy it takes to move the outer most electron
Increases L to Right |
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Electronegativity
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Attraction of an atom for electrons in a chemical bond
Increases L to Right |
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Reasons for trends in ionic radius, ionization energy and electronegativity
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A larger nucleus has more positive protons that keep a tighter grip on its negative electrons
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Valence electrons
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outermost electron
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Atoms can gain or lose electrons to become an ion
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So the outer layer wants to have 8
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Ionic bond
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high electroneg(-) (+)low electroneg
Not shared equally (electrons) higher electroneg "owns" it |
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Covalent bond
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Strong bond, electrons shared evenly
Both atoms valence electrons are 8 |
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Periodic table
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Far right: more electro neg ; more stable
Far left: Less electro neg Far right + Far left = ionic bond |
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What element has the smallest ionic radius?
A) sulfer B) phosphorus C) Magnesium D) Sodium |
The further to right, the smaller the ionic radius
A) sulfer |
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Which two elements would most likely form an ionic bond?
A) Carbon and Nitrogen B) Iodine and Carbon C) Sodium and Iodine D) Two atoms of Bromine |
C) Sodium and Iodine
They are furthest from each other |
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Chemical Reaction
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1. Chem reaction occurs when chemical bonds are broken and new ones are formed
2. In a chemical reaction, matter is never created or destroyed. (law of conservation of matter) 3. EX: when a log is burned (combustion), if you carefully weigh the log before and the ash plus gases that escape afterward, you will find they are equal. |
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Law of conservation
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energy cannot be created or destroyed
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Endothermic reactions
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will not occur without energy being supplied
endothermic (absorb heat) |
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Photosynthesis is an example of _____________
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endothermic reaction (because of light energy)
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Exothermic reaction
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reactions that are spontaneous and do not require energy to be supplied.
Exothermic- give off heat Sodium + Chlorine = NaCl + Energy (example of energy as heat) |
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Which statement is true of photosynthesis reaction?
A) it is exothermic B) The carbon dioxide and sugar molecuels are equal in weight C) As an endothermic reaction, the sum of sugar and oxygen is greater in mass than teh sum of carbon dioxide and water D) The sum of the products, sugar and oxygen, is equal in mass to the sum of the reactants, carbon dioxide and water. |
Mass is NEVER created or destroyed
D) The sum of the products, sugar and oxygen, is equal in mass to the sum of the reactants, carbon dioxide and water. |
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4 Types of reactions:
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1) Synthesis
2) Decomposition 3) Single replacement 4) Double replacement |
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Synthesis
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two or more elements or compounds come together to form a single compound
It is added together |
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Decomposition
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a single compound decomposes into two or more elements or compounds
It is broken down |
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single replacement reaction
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one element switches places and replaces another element.
elements are reversed in the equation |
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double replacement reaction
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2 elements switch places and they replace each other
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What kind of reaction is 2 Al + Fe2O3 ==> Al2)3 + 2Fe
A) Decomposition B) Double displacement C) Single displacement D) SYnthesis |
C) Single displacement
Only 1 compound changes |
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Balanced Equations
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All chem equations must be balanced
Atoms on L must balance on R Make a chart and count out each individual atoms Multiply # infront by subscript of each element, if no subscript, it is 1 If in ( ) like Cu(NO3)2 ==>Cu=1, N=2, O=6 |
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Phases of Matter
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1) atoms and molecules of the same type have a natural attraction to one another
2) Depending on temp and (air) pressure, every form of matter can exist in 3 phases: Solid, liquid, gas |
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0 celcius
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turns water to ice
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Heat
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increases kinetic energy and speeds up molecules
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Icy water
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While heating, icy water will remain at 0 until it completely turns to liquid
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Boil point
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100C
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Gas
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Water at 100C boiling into gas
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Solid to liquid
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Melting
Endothermic reaction |
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Liquid to gas
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Vaporizing
Endothermic reaction |
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Gas to liquid
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Condensing
Exothermic reaction |
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Liquid to solid
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Freezing
Exothermic reaction |
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Solid to gas
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Sublimation
Endothermic reaction |
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Gas to solid
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Deposition
Exothermic reaction |
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Air pressure
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Will change melting and boiling points
increase in pressure - most substances melt and boil at higher temperatures Water= increase pressure causes it to melt at lower temp |
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Density
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the amount of mass in a substance per unit of volume
Measured in units of mass or weight per volume (1cm^3 = 1ml, so cm^3 can be used here) Water density- 1g/1ml |
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Water density
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Items with a greater density than water sink in water
Items with a lesser density float Water density 1g/1ml |
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A liquid boils at 50C. Which of the following will most likely happen if the air pressure is lowered.
A) the liquid will boil at 55C B) the liquid will boil at 45C C) The liquid will freeze at a higher temp D) the liquid will condense at a higher temp |
Decreasing pressure puts less of a "squeeze" on the substance making it easier to boil
Pressure squeezes matter together Squeezing a gas forces particles to be closer together and therefore makes it harder to boil, raising the boiling temperature Conversely, lowering the pressure makes it easier to boil the liquid, lowering the boiling temperature, making : B) the liquid will boil at 45C |
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A 20mk of olive oil weighs 18.36 g. Will 8 g chunk of plastic that has a volume of 11 cm3 float in olive oil?
A) Yes, because the plastic's density is greater than that of oil B) Yes, because the plastic's density is less than that of the oil C) No, because the plastic's density is 0.73g/cm3 D) No, because the oil's density is 0.92 g/cm3 |
Calculate density of both: Weight
_________ Volume Olive oil: 18.36/20 = .92g/cm3 Plastic: 8/1 = .73 g/cm3 Density of plastic is less, so it will float B) Yes, because the plastic's density is greater than that of the oil. |
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Proportionality and Gas Laws
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Direct proportionality has the form : y = kx ; k is constant .... This is a straight line
Increase in X, Increase in Y or Decrease in X, Decrease in Y Inverse prop: Y = k/x ; Increase in x, decrease in y OR Decrease in x, increase in y Exponential proportionality : y= ka^x ; ka are constant ; any parabola (U shaped) graph is likely to exhibit exponential proportionality increase in x = large increase in y decrease in x = large decrease in y Logarithmic proportionality has the form y = k log x and appears as a straight line on a logarithmic scale that increases by a power of 10 every interval increase in x = large increase in y decrease in x = large decrease in y |
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Data show that the greater number of hours nurses work on a shift, the less satisfaction they get from their job. What would a graph of hours versus satisfaction look like?
A) Positive slope, straight line B) Parabola upward C) Flat straight line D) Downward hyperbola |
D) downward hyperbola
A graph of an inverse relationship is downward and hyperbolic in shape |
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Gas laws/ Charles law
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states that temperature and volume are directly proportional:
V1/T1 = V2/T2 Gas laws are carried out in the Kelvin temperature scale: 0= -273C |
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An expandable container has a volume of 1000 ml at a temperature of 27C. The temperature is raised to 47C. What is the new volume of the container?
A) 1740.7 ml B) 2000 ml C) 1066.7 ml D) 2000 ml |
1) switch temp into Kelvin:
T1: 27 + 273 = 300 T2: 47C + 273 = 320 k 2) Volume 1/ Temperature 1 = Volume 2/Temperature 2 1000/300 = V2/320, Solve for V2 C) 1066.7 ml |
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Boyle's law
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pressure and volume are inversely proportional
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Physical Change
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Does not require a change in chemical composition. Water undergoes a physical change when it freezes or melts. Both liquid water and ice have the chemical composition of H20
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Chemical changes
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Require a change in chemical composition. New molecules are formed. Methane, CH4 undergoes a chemical change during combustion. CH4 turns into carbon dioxide and water
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what can break a compound?
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chemical changes
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Heterogeneous mixture
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particles in a mixture are not identical
Milk or muddy water / not clear |
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Homogeneous mixture
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particles are the same;
sugar water or air/ it will be transparent |
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Solution
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homogeneous mixture
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Solute
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substance dissolved in a solution
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Solvent
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the dissolving substance
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Solutions cont
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can take on many forms, air is a solution, so is steel, which is an alloy of iron, carbon and other elements
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Solutions:
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Solvent / Solute / Example
Liquid / Liquid / alcohol in water Liquid / Solid / Sugar in water Liquid / Gas / Oxygen in water Gas / Gas / Nitrogen in air Gas / Solid / Soot in air Solid / Solid / Metal-metal alloy |
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Solubility
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ability to dissolve ; depends on the solvent and solute
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Concentration
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the amount of solute dissovled per liter, can be computed by finding the ration of solute to solvent
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45 Grams of NcCl is dissolved in an 80 ml solution; what is the concentration of NaCl:
A) 37.5% B) 45% C) 56.25% D) 48.8% |
Do a ratio: 45:80
You can see that 45 is over half of 80 Only obvious answer is: C) 56.25% |
