chem112Chapter2

Question 1

the Atomic Theory of Matter

Answer 1

some Greek philosophers thought that there was a smallest particle “atomos” (uncuttable) that made up all of nature

Question 2

“atomos”

Answer 2

means uncuttable

Question 3

Law of Constant Composition

Answer 3

compounds have a definite composition, same number of atoms for the same compounds

Question 4

Joseph Proust

Answer 4

discovered the law of constant composition

Question 5

Law of Conservation of Mass

Answer 5

the total mass of substances present at the end of a chemical process is the same as the mass of substances present before the process took place

Question 6

Antoine Lavoiser

Answer 6

discovered the law of conservation of mass

Question 7

Law of Multiple Proportions

Answer 7

If two elements form more than one compound, the masses of one that combine with a given mass of another are in the ration of small whole numbers, when two or more compounds exist from the same elements, they can not have the same relative number of atoms

Question 8

John Dalton

Answer 8

developed postulates that became scientific law

Question 9

Cathode Rays

Answer 9

streams of negatively charged particles found to emanate from cathode tubes that glow

Question 10

J. J. Thomson

Answer 10

discovered cathode rays

Question 11

Millikan Oil-Drop experiment

Answer 11

determined the charge/mass ratio of the electron

Question 12

Robert Millikan

Answer 12

determined the charge on the electron in 1909

Question 13

Radioactivity

Answer 13

the spontaneous emission of high-energy radiation by an atom

Question 14

Henri Becquerel

Answer 14

first discovered radioactivity

Question 15

Marie and Pierre Curie

Answer 15

also studied radioactivity

Question 16

Three kinds of particles

Answer 16

a particles
b particles
y rays

Question 17

a particles

Answer 17

positively charged +2

Question 18

b particles

Answer 18

negatively charged -1

Question 19

y rays

Answer 19

uncharged

Question 20

plum pudding model

Answer 20

electrons in a positively charged sphere like a raisin cake

Question 21

Ernest rutherford

Answer 21

discovered the nucleus in his gold particle experiment

Question 22

atom size

Answer 22

1-5 Å

Question 23

Isotopes

Answer 23

atoms of the same element with different masses

Question 24

atomic mass unit (amu)

Answer 24

1 amu = 1.66054 x 10^-24

Question 25

spectrometer

Answer 25

measures the atomic mass of a molecule or atom

Question 26

atomic weight

Answer 26

= Ʃ [(isotope mass) × (fractional natural abundance)]

Question 27

rows

Answer 27

periods

Question 28

columns

Answer 28

groups

Question 29

empirical formulas

Answer 29

give the lowest whole-number ratio of atoms of each element in a compound

Question 30

Molecular formulas

Answer 30

give the exact number of atoms of each element in a compound

Question 31

STructural formulas

Answer 31

show the order in which atoms are attached, not the three dimensional shape

Question 32

perspective drawings

Answer 32

show a drawing of a three-dimensional molecule

Question 33

ball and stick models

Answer 33

show a three-dimensional picture of a compound with sticks to show the angles of each bond

Question 34

space-filling models

Answer 34

show a compound if it was to scale

Question 35

ion

Answer 35

formed when an atom of a group of atoms loses or gains electrons

Question 36

cations

Answer 36

formed when at least one electron is lost

Question 37

anions

Answer 37

formed when at least on electron is gained

Question 38

polyatomic ions

Answer 38

formed when groups of atoms gain or lose electrons

Question 39

Ionic compounds

Answer 39

formed between metals and nonmetals

Question 40

chemical nomenclature

Answer 40

naming compounds

Question 41

organic chemistry

Answer 41

the study of carbon

Question 42

hydrocarbons

Answer 42

compounds containing only carbon and hydrogen

Question 43

alkanes

Answer 43

the simplest compounds containing only carbon and hydrogen

Question 44

isomers

Answer 44

two molecules or more molecules that have the same chemical formula

Question 45

can a scientist believe in God?

Answer 45

yes