Unit 3 Test

 

 

†††††††††† 1.†††††††††† A particle of matter contains 6 protons, 7 neutrons, and 6 electrons.This particle must be a

A

neutral nitrogen atom

C

positively charged carbon ion

B

neutral carbon atom

D

positively charged nitrogen ion

 

 

†††††††††† 2.†††††††††† The mass number of an atom is always equal to the total number of its

A

protons only

C

electrons plus protons

B

electrons only

D

protons plus neutrons

 

 

†††††††††† 3.†††††††††† What is the approximate mass of an electron?

A

1 atomic mass unit

C

1/1836 of a proton

B

1/12 of a C-12 atom

D

1836/1837 of a proton

 

 

†††††††††† 4.†††††††††† What is the molar mass of calcium nitrate, Ca(NO3)2?

A

164 g/mole

C

102 g/mole

B

150. g/mole

D

70.0 g/mole

 

 

†††††††††† 5.†††††††††† What is the total number of atoms in 1 mole of calcium?

A

1

C

6.02 x 1023

B

40

D

40(6.02 x 1023)

 

 

†††††††††† 6.†††††††††† What is the mass (in grams) of 3.0 x 1023 molecules of CO2?

A

22 g

B

44 g

C

66 g

D

88 g

 

 

†††††††††† 7.†††††††††† The major portion of an atomís mass consists of

A

electrons and protons

C

neutrons and positrons

B

electrons and neutrons

D

neutrons and protons

 

 

†††††††††† 8.†††††††††† Which atom contains exactly 15 protons?

A

phosphorus Ė 32

C

oxygen Ė 15

B

sulfur Ė 32

D

nitrogen - 15

 

 

†††††††††† 9.†††††††††† Which symbols represent atoms that are isotopes of each other?

A

14C and 14N

B

131I and 131I

C

16O and 18O

D

222Rn and 222Ra

 

 

†††††††††† 10.†††††††† Which pair of atoms contains the same number of neutrons?

A

11H and 32He

B

31H and 32He

C

21H and 42He

D

31H and 42He

 

 

†††††††††† 11.†††††††† The atomic theory proposed by Dalton

A

has been totally discarded

C

has been accepted unchanged to the present day

B

has been expanded and modified

D

has been found to be false

 

 

†††††††††† 12.†††††††† As the average atomic masses of the elements on the Periodic Table increase, the number of atoms in 1 mole of each element

A

decreases

B

increases

C

remains the same

 

 

†††††††††† 13.†††††††† Daltonís atomic theory helped to explain the law of conservation of mass because it stated that atoms

A

could not combine

C

all had the same mass

B

could not be created or destroyed

D

were invisible

 

 

†††††††††† 14.†††††††† Element X has two naturally-occurring isotopes.If the percent abundance of 85X is 72.0% and the percent abundance of 87X is 28.0 %, the average atomic mass of element X is equal to

A

(72.0 x 85) x (28.0 + 87)

C

(0.72 x 87) + (0.28 x 85)

B

(72.0 - 85) x (28.0 + 87)

D

(0.72 x 85) + (0.28 x 87)

 

 

†††††††††† 15.†††††††† How many neutrons does fluorine - 17 have in its nucleus?

A

9

B

8

C

7

D

6

 

 

†††††††††† 16.†††††††† Most of the volume of an atom is made up of the

A

nucleus

B

electron cloud

C

neutrons

D

protons

 

 

†††††††††† 17.†††††††† The atomic number of neon is 10.The atomic number of calcium is 20.Compared with a mole of neon, a mole of calcium contains

A

twice as many atoms

C

an equal number of atoms

B

half as many atoms

D

20 times as many atoms

 

 

†††††††††† 18.†††††††† The nucleus of an atom has all of the following characteristics EXCEPT that it

A

is positively charged

C

contains nearly all of the atomís mass

B

is very dense

D

contains nearly all of the atomís volume

 

 

†††††††††† 19.†††††††† Zinc - 66 (atomic number 30) has

A

30 neutrons

B

35 neutrons

C

36 neutrons

D

96 neutrons

 

 

†††††††††† 20.†††††††† The atomic number of oxygen, 8, indicates that there are eight

A

protons in the nucleus of an oxygen atom

B

oxygen isotopes

C

neutrons outside the oxygen atomís nucleus

D

energy levels in the oxygen atomís nucleus

 

 

†††††††††† 21.†††††††† An aluminum isotope consists of 13 protons, 13 electrons, and 14 neutrons.Its mass number is

A

13

B

14

C

27

D

40

 

 

†††††††††† 22.†††††††† The mass of 2.50 moles of calcium atoms is approximately

A

10.0 g

B

100. g

C

42.5 g

D

250. g

 

 

†††††††††† 23.†††††††† What is the correct number of atomic particles in a neutral atom with an atomic number of 53 and a mass number of 127?

A

protons = 53, electrons = 127, neutrons = 127

B

protons = 53, electrons = 74, neutrons = 74

C

protons = 127, electrons = 127, neutrons = 74

D

protons = 53, electrons = 53, neutrons = 74

 

 

†††††††††† 24.†††††††† According to the law of conservation of mass, when sodium, hydrogen, and oxygen react to form a compound, the mass of the compound is ___ the sum of the masses of the individual elements.

A

equal to

C

less than

B

greater than

D

either greater than or less than

 

 

†††††††††† 25.†††††††† An ion with 5 protons, 6 neutrons, and a charge of +3 has an atomic number of

A

5

B

6

C

8

D

11

 

 

Matching

 

Match the scientist to his contribution to the development of the atomic theory.

A

Bohr

D

Rutherford

B

Chadwick

E

Thomson

C

Dalton

 

 

 

B††††††† 26.†††††††† discovered the neutron

 

E†††††††† 27.†††††††† discovered the electron using a cathode ray tube

 

A††††††† 28.†††††††† postulated that electrons travel around the nucleus in orbits

 

C††††††† 29.†††††††† first published atomic theory;law of conservation of mass

 

D††††††† 30.†††††††† discovered the nucleus using the gold foil experiment

 

Match the terms below with their correct definitions.

A

E

B

F

C

G

D

H

 

 

H††††††† 31.†††††††† Isotope in which the number of neutrons is six more than the isotopeís atomic number

 

B††††††† 32.†††††††† Copper-63

 

F†††††††† 33.†††††††† Copper with seven neutrons more than its atomic number

 

A††††††† 34.†††††††† Isotope that has one neutron more than its number of protons

 

C††††††† 35.†††††††† Carbon with equal numbers of neutrons, protons, and electrons

 

E†††††††† 36.†††††††† Carbon with two more neutrons than its number of protons

 

D††††††† 37.†††††††† Chromium with two more neutrons than its number of protons

 

38.                  Isotope in which the difference between the neutrons and number of protons is 4

G

 

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