1. Answers
(2) D (12) C (22) D (32) C (3) A (13) B (23) A (33) A (4) B (14) C (24) C (34) B (5) D (15) B (25) B (6) C (16) D (26) D (7) C (17) B (27) A (8) A (18) C (28) A (9) A (19) C (29) C (10) D (20) C (30) B (11) B (21) B (31) D

2. The modern model of the atom is based on the work of
iRespond Question F
Multiple Choice
A.) one scientist over a short period of time
B.) one scientist over a long period of time
C.) many scientists over a short period of time
D.) many scientists over a long period of time
E.)

3. In Rutherford's gold foil experiments, some alpha particles were deflected from their original paths but most passed through the foil with no deflection. Which statement about gold atoms is supported by these experimental observations?
iRespond Question F
Multiple Choice
A.) Gold atoms consist mostly of empty space
B.) Gold atoms are similar to alpha particles
C.) Alpha particles and gold nuclei have opposite charges
D.) Alpha particles are more dense than gold atoms
E.)

4. The region labeled "X" in the diagram has a charge that is:
iRespond Question F
Multiple Choice
A.) positive
B.) negative
C.) neutral
D.)
E.)

5. The nucleus of most atoms is made up of:
Multiple Choice
iRespond Question
The nucleus of most atoms is made up of:
A.) protons and electrons
B.) electrons and protons
C.) neutrons and electrons
D.) protons and neutrons
E.)

6. The _______________ constitute(s) most of the volume of an atom.
Multiple Choice
iRespond Question
The _______________ constitute(s) most of the volume of an atom.
A.) nucleus
B.) protons
C.) electron cloud
D.) neutrons
E.)

7. The charge and mass number of a proton are:
Multiple Choice
iRespond Question
The charge and mass number of a proton are:
A.) charge = 0, Mass number = 1
B.) charge = -1, Mass number = 0
C.) charge = +1, Mass number = 1
D.) charge = +1, Mass number = 0
E.)

8. The charge and mass number of an electron are:
Multiple Choice
iRespond Question
The charge and mass number of an electron are:
A.) charge = -1, Mass number = 0
B.) charge = +1, Mass number = 0
C.) charge = 0, Mass number = 1
D.) charge = +1, Mass number = 1
E.)

9. The region labeled "Y" in the diagram has a charge that is:
iRespond Question F
Multiple Choice
A.) positive
B.) negative
C.) neutral
D.)
E.)

10. Most of the mass of the atom can be found in the:
Multiple Choice
iRespond Question
Most of the mass of the atom can be found in the:
A.) charges
B.) electron cloud
C.) electrons
D.) nucleus
E.)

11. In which pair do the particles have approximately the same mass?F
Multiple Choice
iRespond Question
In which pair do the particles have approximately the same mass?
A.) proton and electron
B.) proton and neutron
C.) neutron and electron
D.) neutron and beta particle
E.)

12. Which statement is true about the charges assigned to an electron and a proton?
iRespond Question F
Multiple Choice
A.) Both an electron and a proton are positive
B.) An electron is positive and a proton is negative
C.) An electron is negative and a proton is positive
D.) Both an electron and a proton are negative
E.)

13. The charge and mass number of a neutron are:
Multiple Choice
iRespond Question
The charge and mass number of a neutron are:
A.) charge = +1, Mass number = 0
B.) charge = 0, Mass number = 1
C.) charge = +1, Mass number = 1
D.) charge = -1, Mass number = 0
E.)

14. What is the total charge of the nucleus of a nitrogen atom?
Multiple Choice
iRespond Question
What is the total charge of the nucleus of a nitrogen atom?
A.) -7
B.) 0
C.) +7
D.) +14
E.)

15. F
Multiple Choice
iRespond Question
What is the atomic number of an element that has six protons and eight neutrons?
A.) 2
B.) 6
C.) 8
D.) 14
E.)

16. Compared to a proton, an electron has
iRespond Question F
Multiple Choice
A.) a greater quantity of charge and the same sign
B.) a greater quantity of charge and the opposite sign
C.) the same quantity of charge and the same sign
D.) the same quantity of charge and the opposite sign
E.)

17. What is the total number of electrons in an atom of potassium?
Multiple Choice
iRespond Question
What is the total number of electrons in an atom of potassium?
A.) 18
B.) 19
C.) 20
D.) 29
E.)

18. What is the total number of electrons found in an atom of sulfur?
Multiple Choice
iRespond Question
What is the total number of electrons found in an atom of sulfur?
A.) 6
B.) 8
C.) 16
D.) 32
E.)

19. Which two particles make up most of the mass of an atom?
Multiple Choice
iRespond Question
Which two particles make up most of the mass of an atom?
A.) electron and neutron
B.) electron and proton
C.) proton and neutron
D.) proton and positron
E.)

20. F
Multiple Choice
iRespond Question
What is the mass number of an atom which contains 28 protons, 28 electrons, and 34 neutrons?
A.) 28
B.) 56
C.) 62
D.) 90
E.)

21. What is the total number of neutrons in an atom of an element that has a mass number of 19 and an atomic number of 9?
iRespond Question F
Multiple Choice
A.) 9
B.) 10
C.) 19
D.) 28
E.)

22. The mass number of an atom is determined by:
Multiple Choice
iRespond Question
The mass number of an atom is determined by:
A.) adding the neutrons and electrons
B.) adding the protons and electrons
C.) the number of protons only
D.) adding the neutrons and protons
E.)

23. The nucleus of an atom of cobalt-58 contains
Multiple Choice
iRespond Question
The nucleus of an atom of cobalt-58 contains
A.) 27 protons and 31 neutrons
B.) 27 protons and 32 neutrons
C.) 59 protons and 60 neutrons
D.) 60 protons and 60 neutrons
E.)

24. The nucleus of which atom contains 48 neutrons?
iRespond Question
Multiple Choice F
E.)
D.) 4
B.) 2
A.) 1
C.) 3

25. Atoms of different isotopes of the same element differ in their total number of
iRespond Question F
Multiple Choice
A.) protons
B.) neutrons
C.) electrons
D.)
E.)

26. Isotopes (such as hydrogen-1, hydrogen-2, and hydrogen-3) are atoms of the same element that differ in:
iRespond Question F
Multiple Choice
A.) the number of electrons
B.) the atomic number
C.) the number of protons in the nucleus
D.) the number of neutrons in the nucleus
E.)

27. Which atom contains exactly 15 protons?F
Multiple Choice
iRespond Question
Which atom contains exactly 15 protons?
A.) phosphorus-32
B.) sulfur-32
C.) oxygen-15
D.) nitrogen-15
E.)

28. Which atoms are isotopes of the same element?
iRespond Question
Multiple Choice F
E.)
D.) d
A.) a
C.) c
B.) b

29. The atomic mass of an element is calculated using the
iRespond Question F
Multiple Choice
A.) atomic number and the ratios of its naturally occurring isotopes
B.) atomic number and the half-lives of each of its isotopes
C.) masses and the ratios of its naturally occurring isotopes
D.) masses and the half-lives of each of its isotopes
E.)

30. Calculate the average atomic mass of this element.
Atoms of an unknown element have the following masses and percent abundance: 90.92% of the atoms have a
mass of amu, 0.26% of the atoms have a mass of amu and 8.82% of atoms have a mass of amu.
Calculate the average atomic mass of this element.
iRespond Question F
Multiple Choice
A.) amu
B.) amu
C.) amu
D.) amu
E.)

31. The atomic number of an element is always equal to:
iRespond Question F
Multiple Choice
A.) the number of protons plus the number of neutrons
B.) the number of protons plus the number of electrons
C.) the number of neutrons in the atom
D.) the number of protons in the atom
E.) the number of electrons in the atom

32. F
Multiple Choice
iRespond Question
When you change the number of electrons in an atom, you produce a different
A.) isotope
B.) type of atom
C.) ion
D.) mass number
E.)

33. How many electrons are contained in an Au+3 ion?F
Multiple Choice
iRespond Question
How many electrons are contained in an Au+3 ion?
A.) 76
B.) 79
C.) 82
D.) 197
E.)

34. An ion with 5 protons, 6 neutrons, and a charge of +3 has an atomic number of
iRespond Question F
Multiple Choice
A.) 2
B.) 5
C.) 6
D.) 8
E.) 11
E.)