Let’s talk Chemistry!A common way of defining matter is - anything that has mass and occupies volume (takes up space).Substances that cannot be broken down in to simpler substances areElementsThe chemical formula for water is H2O, this means that each water molecule containsTwo hydrogen atoms and one oxygen atomYou put 1 gram of salt into on liter of water, the result is an example of aHomogeneous mixture – the mixture is the same throughout

The science of what matter is made of and how it changes is

ChemistryThe smallest unit of a substance that behaves like the

substance is aMoleculeThe chemical formula for sulfuric acid is H2SO4. How

many atoms are in one molecule of sulfuric acid?7The chemical formula for table sugar is C12H22O11.

How many oxygen atoms are in each sugar molecule?

11

A material that can be represented by a chemical formula is a

Pure substanceWhat is an example of a gas-liquid mixture?A carbonated drinkThe resistance of a fluid to flow is referred to asViscosityMatter assumes several forms. What state of matter

holds its shape without a container?SolidThe kinetic theory states that the higher the temp thefaster the particles that make up a substance move

The change of a solid directly into a gas isSublimationThe ability to change or to move matter is referred to

asEnergyAll changes of the state of matter requireEnergyEvaporation refers to the change of state from aLiquid to a gasThe law of conservation of mass states that mass Cannot be created or destroyed

During a chemical or physical change, energy may beConverted into another formA liquid changes rapidly into a gas at the liquid’sBoiling pointKnowing the chemical properties of a substance will

tell you how the substanceReacts with other substancesPhysical properties areProperties that can be observed or measured without

changing the composition of matter: appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity, freezing point, etc.

Give an example of a physical change.Ice melting, salt dissolving, water boiling, etc.Volume = mass divided by density. Lead has a density

of 11.3g/cm cubed. What is the volume of a block of lead with a mass of 282.5g?

25 cm cubedWhat is a chemical change?When one or more substances react, they become a

third unique substance often with new physical and chemical properties.

Ice floats in water becauseIce is less dense than water

Digesting food is an example of what kind of change?ChemicalThe tendency of a less dense substance to float in a

more dense liquid is calledBuoyancyWhat makes up the atomic nucleus? What is its

charge?Protons and neutrons; +What is the charge of an electron?- 1Atoms have no electric charge becauseEqual number of protons and electrons

Bohr’s model show electrons behaving likePlanets orbiting the sunModern atomic theory indicates that it is nearly

impossible to determine an electron’s exactPositionAtoms of elements that are in the same group have

the same number ofValence electronsValence electrons determine an atom’sChemical propertiesIonization refers to the process ofLosing or gaining electrons

Oxygen has atomic number 8. This means oxygen has8 protons and 8 electronsAn atom’s mass number equals the number ofProtons + neutrons Where on the periodic table are the alkali metals

found?Left most column of the periodic tableList 3 alkali metalsNa, K, LiMost halogens (group 17) form compounds byGaining an electron to form a negative ion

e-

Cl-

p+ n0

Group 18 noble gases are inert becauseTheir outermost energy level is fullCarbon and other nonmetals are found in which area

of the periodic table?On the right sideA mole is an SI base unit that describes the Amount of a substanceAvogadro’s constant is defined as the number of

particles inOne mole of a pure substanceMolar mass is defined asThe mass in grams of 1 mole of a substance

He

C 23

6.02 x 10

The forces that hold different atoms or ions together are

Chemical bondsA mixture is different from a compound because each

substance in a mixtureRetains its own propertiesEach molecule of hydrochloric acid, HCl, contains one

atom of hydrogen andOne atom of chlorineAn ionic compound is made of _____. Give an

example of a common ionic compound.Ions; NaCl (table salt)

In what form of matter do the molecules have the greatest attractions to one another?

SolidsOften atoms join so that each atom will haveA full outer energy level (gaining or losing electrons)When two hydrogen atoms bond, the positive nucleus

of one atom attracts theNegative electron of the other atomAn ionic bond is a bond that forms betweenIons with opposite chargesSolid ionic compounds have high melting pointsBecause they contain charged ions and are locked

tightly together

In which type of bond do atoms share electrons?Covalent bondsThe name dinitrogen tetroxide tells you that this

compound containsTwo nitrogen atoms and 4 oxygen atomsFormaldehyde, CH2O, and acetic acid, C2H4O2, have

the same empirical formula but differentMolecular formulasA carbon atom can bond to four other atoms because

it has4 valence electrons

Polymers are large organic molecules that are made of

Repeating units (DNA, proteins, starch, plastics, etc.)A protein is a polymer made ofAmino acidsThe “rungs” of the DNA “ladder” are made ofNitrogenous basesA change in color, such as rusting of metal, is a sign

thatA chemical change has occurred or is taking placeA substance that undergoes this change is aReactant C6H12O6 + 6O2 -> 6H2O + 6CO2

A – T C - G

In an exothermic reaction, energy is transferred fromThe reactants to the surroundingsThe energy source in photosynthesis isThe sunA synthesis reaction is a reaction between at least two

compounds in which A + B -> ABA new, more complex compound is formedThe product of the synthesis reaction between

sodium and chlorine gas isSodium chlorideWhen water is broken down by electrolysisThe products are O2 and H2 gases

A chemical equation is balanced by changing or adding

CoefficientsA balanced chemical equation shows the proportions

of reactants and products necessary forMass to be conservedIn the reaction 2Mg + O2 -> 2MgO, the law of definite

proportions states that for every 2 moles of Mg you will need how any moles of O2?

1In a balanced equation, the total mass of productsAlways equals the total mass of reactants

C6H12O6 + _O2 -> _H2O + _CO2

A balanced chemical equation indicates both the number of particles of reactants and products and the number of

MolesWhat factors can speed up a chemical reaction?High pressure, larger surface area, higher

temperature, presence of a catalystLarge, bulky molecules react more slowly than small

ones because they have less opportunity toCollide with other moleculesAn enzyme is a catalyst thatCan speed up specific biological reactions

When a chemical reaction and its reverse are occurring at the same time and at the same rate, the reaction has achieved

EquilibriumWhat is the relationship between chemical

equilibrium and the rates of forward and the reverse reaction?

The forward and reverse reactions must be equalA heterogeneous mixture is one that is notUniform throughoutA homogeneous mixture isUniform throughout

A mixture that separates into different layers when you stop stirring it is

A suspensionYou can usually filter out solid particles in a suspension byUsing a paper filter to catch the particlesYou can skim the fat off the top of a kettle of cold

soup because fat isLess dense than water and rises to the topDistillation can be used to separate solutions of miscible liquids becauseDifferent liquids have different boiling points

Solubility refers to theGrams of solute per 100g of solventLoose sugar dissolves much faster than a sugar cube

because loose sugar hasA greater surface areaYou can make a solute dissolve more quickly In a solvent byHeating the solventWater can dissolve charged particles becauseIts atoms have partial chargesWater is the universal solvent becauseMany different substances dissolve in water

An unsaturated solution is one thatCan dissolve more solute at the current conditionsWhat happens when a supersaturated solution cools

down?The solute will precipitate out of the solutionWhat are some characteristics of bases?Turn litmus paper blue, have a pH over 7, are slippery,

contain hydroxide ionsAcids are substances thatTurn litmus paper red, have a pH under 7, taste bitterA solution that is mildly acidic would have a pH ofApproximately 6

`

The label on a bottle indicates that the substance inside has a pH of 13. This tells you that the substance is

Strongly basicExamples of bases include:Baking soda, oven cleaner, drain cleanerFusion occurs when nucleiCombineThe opposite reaction to fusion isFissionIn the equation E = mc (c is squared)…the c stands forThe speed of light (E – energy, m – mass)