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Problem 45
A chemist in an imaginary universe, where electrons have a different charge than they do in our universe, performs the Millikan oil drop experiment to measure the electron's charge. The charges of several drops are recorded here. What is the charge of the electron in this imaginary universe?
Drop # Charge
A –6.9×10–19 C
B –9.2×10–19 C
C –11.5×10–19 C
D –4.6×10–19 C
Problem 46
Imagine a unit of charge called the zorg. A chemist performs the oil drop experiment and measures the charge of each drop in zorgs. Based on the results shown here, what is the charge of the electron in zorgs (z)? How many electrons are in each drop?
Drop # Charge
A –4.8×10–9 z
B –9.6×10–9 z
C –6.4×10–9 z
D –12.8×10–9 z
Problem 47a
On a dry day, your body can accumulate static charge from walking across a carpet or from brushing your hair. If your body develops a charge of -22 µC (microcoulombs), how many excess electrons has it acquired?
Problem 47b
On a dry day, your body can accumulate static charge from walking across a carpet or from brushing your hair. If your body develops a charge of -22 mC (microcoulombs), what is their collective mass?
Problem 48
How many electrons are necessary to produce a charge of -11.0 C? What is the mass of this many electrons?
Problem 49
Which statements about subatomic particles are true? a. If an atom has an equal number of protons and electrons, it will be charge-neutral. b. Electrons are attracted to protons. c. Electrons are much lighter than neutrons. d. Protons have twice the mass of neutrons.
Problem 50
Which statements about subatomic particles are false? a. Protons and electrons have charges of the same magnitude but opposite sign. b. Protons have about the same mass as neutrons. c. Some atoms don't have any protons. d. Protons and neutrons have charges of the same magnitude but opposite signs.
Problem 51
How many electrons does it take to equal the mass of a proton?
Problem 52
A helium nucleus has two protons and two neutrons. How many electrons does it take to equal the mass of a helium nucleus?
Problem 53a
Write isotopic symbols in the form X-A (e.g., C-13) for each isotope. a. the hydrogen isotope with two neutrons
Problem 53b
Write isotopic symbols in the form X-A (e.g., C-13) for each isotope. b. the gold isotope with 119 neutrons
Problem 53c
Write isotopic symbols in the form X-A (e.g., C-13) for each isotope. c. the gold isotope with 122 neutrons
Problem 53d
Write isotopic symbols in the form X-A (e.g., C-13) for each isotope. d. the uranium isotope with 143 neutrons
Problem 55a
Write isotopic symbols in the form AZX for each isotope. a. the nickel isotope with 32 neutrons
Problem 55b
Write isotopic symbols in the form AZX for each isotope. b. the iron isotope with 30 neutrons
Problem 55c
Write isotopic symbols in the form AZX for each isotope. c. the rubidium isotope with 45 neutrons
Problem 57a
Determine the number of protons and the number of neutrons in each isotope. a. 147N
Problem 57d
Determine the number of protons and the number of neutrons in each isotope. d. 20882Pb
Problem 58
Determine the number of protons and the number of neutrons in each isotope. a. 4019K b. 22688Ra c. 9943Tc d. 3315P
- Determine the number of protons and the number of neutrons in carbon-14 and write its symbol in the form AZX, considering that the amount of carbon-14 in ancient artifacts and fossils is often used to establish their age.
Problem 59
Problem 61
Determine the number of protons and the number of electrons in each ion. a. Ni2+ b. S2– c. Br– d. Cr3+
Problem 62b
Determine the number of protons and the number of electrons in each ion. b. Se2-
Problem 62c
Determine the number of protons and the number of electrons in each ion. c. Ga3+
Problem 62d
Determine the number of protons and the number of electrons in each ion. d. Sr2+
Problem 64a
Predict the charge of the ion formed by each element. a. Sr
Problem 64c
Predict the charge of the ion formed by each element. c. I
Problem 66
Fill in the blanks to complete the table.
Symbol Ion Formed Number of Electrons in Ion Number of Protons in Ion
Cl ______ ______ 17
Te ______ 54 ______
Br Br– ______ ______
______ Sr2+ ______ 38
Problem 70
Write the symbol for each element and classify it as a metal, nonmetal, or metalloid. a. bromine b. potassium c. lead d. silicon e. silver
Problem 71
Determine whether or not each element is a main-group element. a. tellurium b. potassium c. vanadium d. manganese
Problem 72
Determine whether or not each element is a transition element. a. Cr b. Br c. Mo d. Cs
