Unit 2

Question 1

Matter

Answer 1

Anything that has mass and occupies space. Compound, element, mixture

Question 2

Two types of matter

Answer 2

Heterogeneous and homogeneous

Question 3

Compound

Answer 3

Two or more elements with new properties unlike the properties of the original substance. Example table salt

Question 4

Element

Answer 4

Only one kind of Atom. can no longer be decomposed by ordinary chemical means. example silver

Question 5

Mixture

Answer 5

Material composed of two or more substances which retain its own physical properties. Hetero or Homo. Also called solution

Question 6

Changes that matter undergoes-physical properties

Answer 6

No change in composition. example mass, length, volume. Mixtures separated using their physical properties.

Question 7

Changes that matter undergoes-physical change

Answer 7

-No new kinds of matter are formed -phase changes example freezing, boiling
mixtures can be separated by physical separation

Question 8

Changes that matter undergoes-chemical properties

Answer 8

Changes into something new. Does it burn? React with acids?

Question 9

Changes that matter undergoes-chemical changes

Answer 9

Changes that produce new kinds of matter that show brand-new properties. Example combustion burning, composition and decomposition, gas is given off

Question 10

Law of definite composition

Answer 10

A compound always contains elements in certain definite compositions by having the same percentage by mass of each element in the compound

Question 11

Law of multiple proportions

Answer 11

There can exist 2 or more compounds with different proportions of the same elements

Question 12

Atomic number

Answer 12

Equals number of protons

Question 13

Mass number

Answer 13

Equals number of protons plus number of neutrons

Question 14

Atomic mass

Answer 14

Mass of Atom in AMU’s or u

Question 15

Determining number of neutrons

Answer 15

Mass number-atomic number

Question 16

Isotopes

Answer 16

Same Atom, different mass, different number of Neutrons

Question 17

Why do protons not repel?

Answer 17

Strong nuclear force which is the strongest in the universe

Question 18

Avogadro’s number

Answer 18

6.02x10^23

Question 19

Mole

Answer 19

Amount of the substance that contains 6.02×10^23rd of any kind of chemical unit

Question 20

Sig fig rule 1: 1-9

Answer 20

If answer starts with a digit 1-9 AND has decimal anywhere in number, ALL figures are significant (including zeroes)

Question 21

Sig fig rule 2: 0 then decimal

Answer 21

If an answer starts with a zero and decimal, look to the first digit 1-9. That digit and all that follow (including zeroes) are significant.

Question 22

Sig fig rule 3: 1-9 no decimal

Answer 22

All digits are significant unless the answer ends in zeros. Then all digits are significant except the last zeros.

Question 23

Sig fig with addition and subtraction

Answer 23

Data with least number of decimal points decides the number of decimal points in the answer.

Question 24

Sig figs with multiplication or division

Answer 24

Answer contains the same number of sig figs as the datum with the least number of sig figs.

Question 25

Molar mass

Answer 25

Mass in grams of one mole of naturally occurring atoms of an element. G/mol

Question 26

Physical properties

Answer 26

Color, density, solubility, taste, melting point, hardness, smell, malleability

Question 27

Chemical properties

Answer 27

Flammable, can neutralize base, combustible, reacts to form gas, reacts to form precipitate

Question 28

Physical changes

Answer 28

Melting, evaporation, rain, water to steam, salt dissolving in water, pepper suspended in water, crushing medicine, metal pulled to a wire

Question 29

Chemical changes

Answer 29

Wood rotting, milk sours, sugar to caramel, iron rusts, changes colors, alka seltzer in water.