Unit 2 / Classification of Matter

Question 1

matter

Answer 1

occupies space/has mass (inertia)

Question 2

composition

Answer 2

quantitative description of a sample’s components (usually %)

Question 3

atoms

Answer 3

smallest entities in chemistry, not created or destroyed in chemical reactions

Question 4

elements

Answer 4

can’t be decomposed by chemical means, contains a “single type” of atoms (same atomic #, “Z”)

Question 5

compound

Answer 5

matter of fixed composition, atoms of 2 or more elements; can be decomposed by chemical means

Question 6

substance

Answer 6

form of matter with definite composition; elements and compounds

Question 7

physical separation techniques

Answer 7

distillation, filtering, precipitating

Question 8

mixtures

Answer 8

composition is variable

Question 9

homogenous

Answer 9

uniform to the unaided eye (solutions)

Question 10

heterogeneous

Answer 10

non uniform to the unaided eye (ex. sand)

Question 11

systematic / determinate error

Answer 11

affects accuracy, measurements are either always high or always low (Taylor’s truck speedometer)

Question 12

random / indeterminate error

Answer 12

affects precision, measurements are sometimes high, sometimes low; result is expected to be the same but a distribution of values is observed

Question 13

what determines chemical properties?

Answer 13

electrons

Question 14

particles in a nucleus?

Answer 14

protons and neutrons

Question 15

mass of atoms is determined by…

Answer 15

experiment, never calculation!

Question 16

isotopes

Answer 16

different number of neutrons, but same element

Question 17

the number of protons in the nucleus…

Answer 17

is the atomic number

Question 18

mass number

Answer 18

sum of protons, neutrons in the nucleus and a natural #

Question 19

molecular mass (amu)

Answer 19

mass of one molecule

Question 20

molar mass (g/mol)

Answer 20

mass of one mole