chapter 2: atoms, molecules,, and ions Flashcards Preview

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Flashcards in chapter 2: atoms, molecules,, and ions Deck (219):
1

question of whether matter is or isn't ... led to many ....

continuous; experiments

2

antoine Lavoisier's experiments resulted in the

law of conservation of mass

3

law of conservation of mass: mass is neither ... nor .. during

gained; destroyed; chemical reactions

4

law of constant composition: all samples of pure substance have the

same elements in the same proportions by mass

5

law of multiple proportions: for compounds that are formed by the same elements, the masses of the first element that combine with a certain mass of the second element is always

a ratio of small whole numbers

6

Democritus proposes matter is ... and called the smallest particles of matter...

discontinuous; atoms

7

(Dalton's theory) all matter is made up of

atoms

8

(Dalton's theory) atom: smallest unit of an element that

retains the properties of the element

9

(Dalton's theory) element is made up of one type of ..., and the properties of the atoms of an element are ..

atom; identical

10

(Dalton's theory) compounds have atoms of

2 or more elements

11

(Dalton's theory) the number of atoms in a compound is

the same

12

(Dalton's theory) atoms merely...during chemical reactions

rearrange

13

(Dalton's theory) explanation of law of constant composition: compounds are always composed of the same

atoms in the same ratios

14

(Dalton's theory) explanation of the law of multiple proportions: compounds can be made from the same elements in different ratios in which the ratio of atoms will be

whole numbers

15

(Dalton's theory) explanation of law of conservation of mass: in chemical reactions, atoms are merely ...., ...., and ....; since the number of atoms and the atoms themselves aren't changing, the mass

rearranged; combined; separated; doesn't change either

16

atoms can be ... into several different ..

subdivided; subatomic particles

17

the three major subatomic particles comprising atoms include:

protons, neutrons, and electrons

18

the manner in which atoms combine and behave is determined by the ... and .. of each subatomic particle

number; type

19

JJ Thomson used a gas discharge tube to show that cathode rays were

electrically charged particles

20

cathode rays traveled in .... and were deflected by ... and ...

straight lines; electric and magnetic fields

21

Thomson determined by the direction of the rays' deflection that the particles were

negatively charged

22

electrons:

negatively charged particles

23

Robert A. Milikan measured the

charge of the electron

24

(Milikan's experiment) exposed tiny oil drops to

high-energy radiation

25

(Milikan's experiment) measured the rate that the electrically charged oil droplets fell in the

presence/absence of an electric field

26

(Milikan's experiment) calculated the ... on the oil drop

charge

27

(Milikan's experiment) noted that the charge was a multiple of a

single quantity

28

(Milikan's experiment) this quantity is the charge of an

electron (e)

29

with the knowledge of the charge, the ... of the electron was measured

mass

30

in a study meant to analyze deflection of alpha particles as they passed through gold foil, Rutherford recognized that some of the alpha particles were

deflected back toward the source

31

Rutherford proposed a nuclear model of the atom, which suggested that atoms contain

nuclei of positive charge

32

nucleus contains most of an atom's

mass

33

electrons comprise most of the atom's

volume

34

Rutherford found that every element has a different

positive charge

35

Rutherford suggested the existence of a

proton

36

the mass of the proton is ... times that of the electron

1836

37

Rutherford was unable to explain why protons were,....., considering that .... between like charges typically exists

close together; repulsion

38

the existence of a neutral particle was proposed because the proton didn't account for

the entire nuclear mass

39

james chadwick discovers

neutrons

40

neutron's mass is close to that of a

proton

41

strong nuclear binding forces hold the particles of nuclei

together

42

ratio of neutrons to protons is around:

1.0 to 1.6

43

charges of the electron and proton are equal in

magnitude.

44

atoms contain equal numbers of

electrons and protons

45

mass of protons and neutrons are almost equal, while the mass of an electron is

very small

46

atomic number (Z): amount of .. in an atomic nucleus; ... an element

protons; identifies

47

number of neutrons in atoms of the same element are not always the same:

isotopes

48

mass number (A): amount of

protons and neutrons in an atom

49

isotopes have the same ... but different ..

atomic number; mass numbers

50

most elements occur in nature as mixtures of

stable isotopes

51

about 75% of naturally occurring elements have

2 or more stable isotopes

52

isotopes disproves one aspect of

Dalton's atomic theory

53

to portray specific isotopes, the following notation is used:

a X
z

54

X→

element's symbol

55

a→

mass number

56

z→

atomic number

57

the atomic number and element's symbol do not both have to be included, because either one can

identify the element

58

ions: charged atoms that are formed when atoms

lose/gain electrons

59

cation: ... formed when an atom ... one or more electrons

positive ion; loses

60

anion: ....; formed when an atom ... one or more electrons

negative anion; gains

61

notation used to identify ions, and notation used to identify isotopes can be

combined

62

atomic mass unit (u):

1/12 mass of Carbon-12 atom

63

atomic mass unit is the standard unit to measure

atomic mass

64

all other atomic masses are compared with the

Carbon-12 standard

65

1 u =

1.66 x 10-27 kg

66

masses of neutrons and protons are approximately

1 u

67

atomic masses of all the elements found with

mass spectrometers

68

(mass spectrometer) a sample of an element in gaseous form is exposed to a beam of high energy electrons which convert the atoms of the element to

cations

69

(mass spectrometer) a magnetic field deflects the cations into a

curved path

70

(mass spectrometer) the degree of curvature determines the

mass and charge of the ion

71

(mass spectrometer) the charge to mass ratio of the ions is then

calculated

72

mass spectrometer measures .. and .... of isotopes in a sample of an element

masses; relative abundance

73

isotopic compositions of most naturally occurring elements are ... and aren't influenced by the ... of the sample

constant; origin

74

isotopic mass: mass of an

isotope of a given element

75

a weighted average mass can be calculated that considers the

abundance of isotopes

76

atomic mass: weighted ... of the naturally occurring element

average mass

77

atomic mass is an average: portrays natural isotopic

distribution of an element

78

classification of elements enables comprehension of

elements' properties

79

periodic table arranges the elements into ..., with elements of similar properties falling in the same ...

rows; column

80

Mendeleev initially arranged elements by increasing ...., although he deviated from this to place elements with similar ... together

atomic mass; properties

81

Mendeleev predicted the existence of other

elements

82

Moseley ordered the elements based on their

atomic numbers

83

period: ... of the periodic table

horizontal row

84

properties of elements vary across

periods

85

groups: .... of the periodic table

columns

86

properties of elements in the same groups are

similar

87

numbers associated with rows refer to the outermost ... in which electrons can be found in their ground state

energy level

88

numbers associated with groups can provide insight into the .... in the outermost energy level of an atom

electron configuration

89

classification of elements also involves indicating whether the elements are

metals, nonmetals, or metalloids

90

metal:

shiny, good electrical conductor

91

nonmetals: elements that don't ..., elements in ... part of the periodic table

conduct electricity; top right

92

metalloids: have properties of ... and ....; .... of electricity; elements along the line that divides ... and ....

metals nonmetals; semiconductors; metals; nonmetals

93

representative/ main-group elements: elements in groups

1,2, 13-18

94

transition metals: ... block elements from group ..

d; 3-12

95

lanthanides: elements that follow

lanthanum

96

actinides: elements that follow

actinium

97

inner transition metals:

lanthanides and actinides

98

alkali metals (group 1):

soft, low melting metals, reactive, abundant

99

alkali metal reactivity increases

down the group

100

alkali metals occur in compounds rather than as

free elements

101

alkaline earth metals (group 2) less reactive than

alkali metals

102

Mg and Ca are

abundant

103

halogens (group 17): term means

salt formers

104

halogens (group 17): among most reactive

nonmetals

105

halogens (group 17): reactivity decreases down the

group

106

halogens (group 17): fluorine is the most ... of all the elements

reactive

107

chlorine is the most ... of the halogens

abundant

108

noble gases (group 18): generally

unreactive

109

molecule: combination of atoms that acts as a single particle due to the strong

attraction between the atoms

110

molecules are electrically

neutral

111

molecules of different atoms form

molecular compounds

112

diatomic molecules consist of

2 atoms

113

if all the atoms in a molecule are the same, the substance is

an element

114

if atoms of two or more elements are present, the substance is a

molecular compound

115

molecular formula: shows the ... of a molecule and indicates the number of each

composition; type of atom in a molecule

116

subscripts give the number of

atoms of an element

117

structural formula: shows how atoms are c

connected in a molecule

118

molecular mass: sum of the masses of a molecule's

atoms

119

molecular mass is expressed in

atomic mass units

120

the number of sig figs when calculating atomic mass is sometimes

random

121

(atomic mass) use either one or two digits after the decimal point, whichever corresponds with the

precision that is wanted

122

some compounds contain elements in the form of

ions

123

ionic compound: compound do

cations and anions that are joined together

124

ionic compounds are held together by

electrostatic forces

125

all ionic compounds are electrically neutral because the sum of the charges of the cations and anions equal

zero

126

the exact number of ions in an ionic crystal varies with the

size of the sample

127

empirical formula: gives the relative numbers of atoms in a substance with the smallest possible

whole-number subscripts

128

empirical formulas of ionic compounds indicate

electrical neutrality

129

empirical formulas of ionic compounds indicate

electrical neutrality

130

metals form

cations

131

nonmetals form

anions

132

for groups 1-3, the metals form cations that have charges that are equal to their

group numbers

133

main group nonmetals form anions that have charges based on their distance from the

noble gases

134

when charges of ions in an ionic compound are known, the formula is written by adjusting the ... on the ions so that the sum of charges is ...

ions; zero

135

monatomic ions: ions that are formed from

single atoms

136

polyatomic ion: group of atoms with a

charge

137

polyatomic ions behave like a .... because of the

single particle; strong attractive forces

138

ammonium is the most common

polyatomic cation

139

empirical formula of an ionic compound with polyatomic ions is also dependent on

charges

140

formula mass: sum of atomic masses of all atoms in an ionic compound's

empirical formula

141

formulas for ionic compounds give the relative numbers of

cations and anions

142

for monatomic ions: cation is named by the element's ...; anion is the root of the element name with suffix ...

name; -ide

143

binary compounds: comprised of

2 elements

144

name of binary compounds doesn't include

numerical prefixes

145

name of polyatomic ions are used in the

compound name

146

metals from other groups can have more than one

cation

147

.... used to specify the charges of metals that have more than one cation

roman numerals

148

older system with suffixes ... and ... to indicate charges

-ous; -ic

149

acids: produce ... in aqueous solution

hydrogen ions

150

when the name of the anion ends in -ide (exception: hydroxide), acid name is found by adding prefix ... and changing the ending to ..; followed by the word ..

hydro-; -ic; acid

151

anions found in acids combine with a sufficient number of hydrogen ions to give

electrical neutrality

152

if polyatomic anion ends in -ate, the name of the acid will end in ... followed by ..

-ic; acid

153

if polyatomic anion ends in -ite, the name of the acid will end in ... followed by ...

-ous; acid

154

(molecular compounds) element father to the left in the periodic table is given

first

155

(molecular compounds) element closer to the bottom in any group is given

first

156

(molecular compounds) We name the 1st element in the compound followed by the name of the 2nd element with its ending changed to

ide

157

prefixes indicate the number of atoms of each element in

a molecule

158

(molecular compounds) hydrogen is given second when it combines with elements from groups

1A to 5A

159

(molecular compounds) hydrogen is first when it combines with group

6A and 7A

160

oxygen is always last, except when it combines with

fluorine

161

general order in which elements are given in a molecular compounds formula:

B, Si, C, As, P, N, H, Se, S, I, Br, Cl, O, F

162

organic compounds: compounds that have

carbon

163

hydrocarbons: organic compounds that only have

hydrogen and carbon

164

alkanes: simplest class of

hydrocarbons

165

general formula for alkanes is:

CnH2n+2

166

alkanes have an ... ending

-ane

167

(alkanes) linear chains of carbon with enough hydrogen sot that each carbon is connected to

4 other atoms

168

alkanes with more than three carbon atoms may have different arrangements of carbon chain that have

branching

169

for those that are branched, the substituent attached to the longest chain is the

alkyl group

170

names of alkanes are based on the length of the

hydrocarbon chain

171

n-alkanes are

straight, unbranched chains

172

(names of alkanes) methane

CH4

173

(names of alkanes) ethane

C2H6

174

(names of alkanes) propane

C3H8

175

(names of alkanes) n-Butane

C4H10

176

(names of alkanes) n-Pentane

C5H12

177

(names of alkanes) n-Hexane

C6H14

178

(names of alkanes) n-Heptane

C7H16

179

(names of alkanes) n-Octane

C8H18

180

(names of alkanes) n-Nonane

C9H20

181

(names of alkanes) n-Decane

C10H22

182

(names of alkanes) methyl

CH3 -

183

(names of alkanes) ethyl

C2H5 -

184

(names of alkanes) propyl

C3H7 -

185

(names of alkanes) butyl

C4H9 -

186

(names of alkanes) pentyl

C5H11 -

187

(names of alkanes) hexyl

C6H13 -

188

(names of alkanes) Heptyl

C7H15 -

189

(names of alkanes) Octyl

C8H17 -

190

(names of alkanes) Nonyl

C9H19-

191

(names of alkanes) decyl

C10H21 -

192

cycloalkanes: hydrocarbons that contain a

ring of carbon atoms

193

cycloalkanes formula

CnH2n

194

substituents of cylcoalkanes are named in the same manner as alkanes, except they have the prefix

cyclo-

195

When branching occurs in alkanes, branched hydrocarbon substituents are referred to as ... and the ane ending is removed and a ... ending is added

alkyl groups; -yl

196

(naming alkanes) locate the longest .. or biggest ..

chain; ring

197

(naming alkanes) locate substituents and number the chain to minimize the number of the

substituent

198

(naming alkanes) name the substituent, properly located on the chain by a number followed by a

dash

199

(naming alkanes) add the base alkane name of the longest

carbon chain

200

more complex organic compounds have

functional groups

201

functional groups: atoms/ small groups of atoms that undergo

reactions

202

halogesn are

functional groups

203

molecular compounds form when two or more

nonmetals combine

204

(ionic solids) 3d structure held by strong

electrostatic orces

205

(ionic solids) hard, brittle

crystalline solids

206

(ionic solids) high melting

points

207

(ionic solids) must be heated to very high temperatures to be

vaporized

208

(ionic solids) when ionic substances dissolve they separate into

cations and anions (dissociation)

209

(ionic solids) when ionic substances that have polyatomic ions dissolve, the polyatomic ions do not

separate

210

(ionic solids) measuring electrical conductivity distinguishes ionic compounds from most

molecular compounds

211

(ionic solids) solid ionic compounds don't

conduct electricity

212

(ionic solids) electrolyte: substance that produces ions when

dissolved in water; conduts electricitiy

213

(ionic solids) pure water and solutions of most other molecular compounds are poor electrical conductors→

nonelectrolyte

214

(small molecular compounds) typically exist as .., ..., or ...

gases; liquids; low-melting solids

215

(small molecular compounds) forces that hold one molecule to another are

weak

216

(small molecular compounds) low melting

points

217

(small molecular compounds) in liquid phase: molecules are close but can

move

218

(small molecular compounds) in gas phase: molecules are moving and

far apart

219

(small molecular compounds) no phase conducts

electricity