Modern Chemistry: Chapters 1 & 2 Review

chemistry

the study of properties of substances and how they react with each other

hypothesis vs. theory vs. law

a hypothesis is a testable theory, whereas a theory is a well-supported explanation of why something happens, and a law is a descriptive summary of what happens

example of a heterogeneous mixture

oil and water

heterogeneous mixture

composition of the mixture is NOT uniform throughout

example of a homogeneous mixture

salt and water

homogeneous mixture

composition of the mixture is uniform throughout

liquids have ___ volume, but ____ shape.

definite, no definite

gases have ___ volume and ___ shape

no definite, no definite (volume changes to size/shape of container)

solids have ___ shape and ___ volume

definite, definite

extensive properties

dependent on the amount of matter being considered

intensive properties

not dependent on the amount of matter being considered

examples of extensive properties

mass, length, volume

examples of intensive properties

boiling point, melting point, magnetism, density, and temperature

extensive properties are used to form

constants (e.g. density)

mass SI Unit

kilogram (kg)

length SI unit

meter (m)

temperature SI unit

kelvin (K)

chemical change

alters the composition or identity of a substance (reaction)

physical change

does NOT alter the composition of identity of a substance (e.g. ice melting)

separation technique that uses differences in boiling points to separate components of a mixture

distillation

compound

two or more elements chemically combined in fixed proportions

panning

separates mixtures based on density

element

a substance that cannot be broken down into simpler substances via ordinary chemical means

matter

anything that occupies space and has mass

mixture

a combination of two or substances that retain their distinct identities

theory

a well tested explanation for a body of facts

filtration

separates mixtures based on solubility

law

a relationship that is always true under the same conditions

quantitative observation

a numerical observation

qualitative observation

a description using words

scientific method

a systematic approach to research

steps of the scientific method

1. make observations

2. develop questions

3. formulate a hypothesis

4. controlled experiment

5. check results

density

how much mass is packed into a given space (volume)

density equation

d = m/v

how to convert Celsius to Kelvin

+ 273.15

how to convert L to mL

multiply L by 1000

silver

element

air

mixture

water

compound

salt water

mixture

nitrogen

element

T/F: a chemical change creates a new substance with different chemical properties

True

Is color an intensive or extensive property?

intensive

power of ten of a kilogram

10^3

power of ten of a milligram

10^-3

power of ten for centimeter

10^-2

mL to L

mL / 1000

what is true about an elements ability to be broken down chemically

it cannot be broken down into simpler substances via chemical reactions

what is true of a mixture regarding the identities of its component substances

the substances retain their distinct properties

what is true of a compound regarding how its atoms are combined

they have a fixed ratio and chemical bonds

three states of matter

solid, liquid, gas

what temperature in Celsius does water boil?

100*C

Is density an extensive or intensive property?

intensive

diatomic molecule

chemical composed of exactly two atoms

how to tell if an element naturally occurs as a diatomic molecule

ends in gens or ines

example of homonuclear diatomic molecules

oxygen, hydorgen, chlorine, fluorine, nitrogen

What two elements are liquid at room temperature?

(Br) Bromine and (Hg) Mercury

Y/N: do the products of a chemical reactions have the same properties as the reactions that formed them?

no