1. University of Kentucky
Clicker Questions
Chapter 2
Atoms and Elements
Allison Soult
University of Kentucky

2. The law of definite proportions The law of multiple proportions
Two samples of the same compound are compared: Sample 1: g carbon and g oxygen Sample 2: g carbon and g oxygen This data shows which of the following?
The law of definite proportions
The law of multiple proportions
The law of conservation of mass
a and b only
a, b, and c
Answer: a

3. The law of definite proportions The law of multiple proportions
Two samples of the same compound are compared: Sample 1: g carbon and g oxygen Sample 2: g carbon and g oxygen This data shows which of the following?
The law of definite proportions
The law of multiple proportions
The law of conservation of mass
a and b only
a, b, and c
Answer: a

4. What information about atomic structure was determined by Millikan’s oil drop experiment?
Presence of electrons
Presence of nucleus
Charge on an electron
Charge on a neutron
Charge on a proton
Answer: c

5. What information about atomic structure was determined by Millikan’s oil drop experiment?
Presence of electrons
Presence of nucleus
Charge on an electron
Charge on a neutron
Charge on a proton
Answer: c

6. Nothing can penetrate a carbon atom.
Which of the following statements about a carbon atom is correct according to the plum-pudding atom model?
Nothing can penetrate a carbon atom.
The carbon atom has a positive charge.
The positive charge is distributed over the sphere of the atom.
The carbon atom has a negative charge.
Answer: c

7. Nothing can penetrate a carbon atom.
Which of the following statements about a carbon atom is correct according to the plum-pudding atom model?
Nothing can penetrate a carbon atom.
The carbon atom has a positive charge.
The positive charge is distributed over the sphere of the atom.
The carbon atom has a negative charge.
Answer: c

8. Which scientist confirmed that most of an atom’s mass and all of its positive charge are contained in a small core called the nucleus?
John Dalton
Joseph Proust
J. J. Thomson
Ernest Rutherford
Robert Milliakn
Answer: d

9. Which scientist confirmed that most of an atom’s mass and all of its positive charge are contained in a small core called the nucleus?
John Dalton
Joseph Proust
J. J. Thomson
Ernest Rutherford
Robert Milliakn
Answer: d

10. Which of the following determines the identity of an atom?
Number of protons
Number of electrons
Number of neutrons
Total number of protons and neutrons
Total number of protons and electrons
Answer: a

11. Which of the following determines the identity of an atom?
Number of protons
Number of electrons
Number of neutrons
Total number of protons and neutrons
Total number of protons and electrons
Answer: a

12. How many neutrons are in 1000 atoms of Cl-37?
37,000 20
20,000
Cannot be determined
Answer: d

13. How many neutrons are in 1000 atoms of Cl-37?
37,000 20
20,000
Cannot be determined
Answer: d

14. How many protons are in an atom of 195Pt?
273
195
117 78
Answer: d

15. How many protons are in an atom of 195Pt?
273
195
117 78
Answer: d

16. Which of the following statements is true about ions?
An ion is the result of an atom gaining a neutron.
A positively charged ion results from the gain of a proton.
A negatively charged ion results from the loss of a proton.
The gain or loss of an electron by an atom will result in an ion.
None of the above.
Answer: d

17. Which of the following statements is true about ions?
An ion is the result of an atom gaining a neutron.
A positively charged ion results from the gain of a proton.
A negatively charged ion results from the loss of a proton.
The gain or loss of an electron by an atom will result in an ion.
None of the above.
Answer: d

18. To form an ion, aluminum is most likely to
gain three electrons to become Al3–.
lose three electrons to become Al3+.
gain three protons to become Al3+.
lose three protons to become Al3–.
Answer: b

19. To form an ion, aluminum is most likely to
gain three electrons to become Al3–.
lose three electrons to become Al3+.
gain three protons to become Al3+.
lose three protons to become Al3–.
Answer: b

20. If a pure copper penny has 2.94 × 1022 atoms, what will be its mass?
1.30 g
0.323 g
2.79 g
3.10 g
1.12 g
Answer: d

21. If a pure copper penny has 2.94 × 1022 atoms, what will be its mass?
1.30 g
0.323 g
2.79 g
3.10 g
1.12 g
Answer: d

22. Which of the following elements is an alkali earth metal?Fe Ca Ge Pb
Answer: c

23. Which of the following elements is an alkali earth metal?Fe Ca Ge Pb
Answer: c

24. Which of the following elements will have properties most similar to tin, Sn (50)?
Lead, Pb (82)
Gallium, Ga (31)
Zinc, Zn (30)
Titanium, Ti (22)
Arsenic, As (33)
Answer: a

25. Which of the following elements will have properties most similar to tin, Sn (50)?
Lead, Pb (82)
Gallium, Ga (31)
Zinc, Zn (30)
Titanium, Ti (22)
Arsenic, As (33) Sn Pb
metal
very malleable
SnO, SnO2
PbO, PbO2
SnCl2, SnCl4
PbCl2, PbCl4
Answer: a

26. Not enough information to determine
Boron has two naturally occurring isotopes: B-10 with an isotopic mass of amu B-11 with an isotopic mass of amu Calculate the percent abundance for each isotope if the average atomic mass of boron is amu.
50.0% B-10, 50.0% B-11
25.0% B-10, 75.0% B-11
19.8% B-10, 80.2% B-11
26.4% B-10, 73.6% B-11
Not enough information to determine
Answer: c

27. Not enough information to determine
Boron has two naturally occurring isotopes: B-10 with an isotopic mass of amu B-11 with an isotopic mass of amu Calculate the percent abundance for each isotope if the average atomic mass of boron is amu.
50.0% B-10, 50.0% B-11
25.0% B-10, 75.0% B-11
19.8% B-10, 80.2% B-11
26.4% B-10, 73.6% B-11
Not enough information to determine
Answer: c

28. The atomic mass of Ga is the average of 68.9 and 71.9.
The mass spectrum of gallium, Ga, is shown as follows. The atomic mass of Ga is 69.7 amu. Which of the following statements is correct?
All Ga atoms weigh 69.7 amu.
The atomic mass of Ga is the average of 68.9 and 71.9.
The atomic mass of Ga will be closer to 69 than 71 because there are more atoms that weigh 68.9 amu.
Answer: c

29. The atomic mass of Ga is the average of 68.9 and 71.9.
The mass spectrum of gallium, Ga, is shown as follows. The atomic mass of Ga is 69.7 amu. Which of the following statements is correct?
All Ga atoms weigh 69.7 amu.
The atomic mass of Ga is the average of 68.9 and 71.9.
The atomic mass of Ga will be closer to 69 than 71 because there are more atoms that weigh 68.9 amu.
Answer: c

30. Which of the following is FALSE?
The mole can be used to specify Avogadro’s number of anything.
Avogadro’s number, × 1023, is an exact number.
The mole is equal to the number of atoms in exactly 12 grams of carbon-12.
The value of an element’s molar mass in grams per mole is numerically equal to the element’s atomic mass in amu.
Answer: b

31. Which of the following is FALSE?
The mole can be used to specify Avogadro’s number of anything.
Avogadro’s number, × 1023, is an exact number.
The mole is equal to the number of atoms in exactly 12 grams of carbon-12.
The value of an element’s molar mass in grams per mole is numerically equal to the element’s atomic mass in amu.
Answer: b

32. Which weighs more, a pea or a marble?
Answer: b

33. Which weighs more, a pea or a marble?
Answer: b

34. Which has more atoms, 10.0 g Mg or 10.0 g Ca?
Magnesium
Calcium
Both have the same number of atoms.
Answer: a

35. Which has more atoms, 10.0 g Mg or 10.0 g Ca?
Magnesium
Calcium
Both have the same number of atoms.
Answer: a

36. Calculate the mass in grams of one mole of footballs if one football has a mass of 0.43 kg.
Answer: c

37. Calculate the mass in grams of one mole of footballs if one football has a mass of 0.43 kg.
Answer: c

38. Which of the following has the largest mass?
10.0 g Li
10.0 moles of Li
100 g Na
10.0 moles of K
100 g Rb
Answer: d

39. Which of the following has the largest mass?
10.0 g Li
10.0 moles of Li
100 g Na
10.0 moles of K
100 g Rb
Answer: d