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Problem 44
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 45a
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 -15 µC (microcoulombs), how many excess electrons has it acquired?
Problem 45b
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 -15 µC (microcoulombs), what is their collective mass?
Problem 46
How many electrons are necessary to produce a charge of -1.0 C? What is the mass of this many electrons?
Problem 47
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 48
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 49
How many electrons does it take to equal the mass of a proton?
Problem 50
A helium nucleus has two protons and two neutrons. How many electrons does it take to equal the mass of a helium nucleus?
Problem 51a
Write isotopic symbols in the form X-A (e.g., C-13) for each isotope. a. the silver isotope with 60 neutrons
Problem 51b
Write isotopic symbols in the form X-A (e.g., C-13) for each isotope. b. the silver isotope with 62 neutrons
Problem 51c
Write isotopic symbols in the form X-A (e.g., C-13) for each isotope. c. the uranium isotope with 146 neutrons
Problem 51d
Write isotopic symbols in the form X-A (e.g., C-13) for each isotope. d. the hydrogen isotope with one neutron
Problem 52a
Write isotopic symbols in the form AZX for each isotope. a. the copper isotope with 34 neutrons
Problem 52b
Write isotopic symbols in the form AZX for each isotope. b. the copper isotope with 36 neutrons
Problem 52c
Write isotopic symbols in the form AZX for each isotope. c. the potassium isotope with 21 neutrons
Problem 53a
Determine the number of protons and the number of neutrons in each isotope. a. 147N
Problem 53d
Determine the number of protons and the number of neutrons in each isotope. d. 20882Pb
Problem 54
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 55
- Determine the number of protons and neutrons in uranium-235, which is used in nuclear fission, and write its symbol in the form AZX.
Problem 56
Problem 57
Determine the number of protons and the number of electrons in each ion. a. Ni2+ b. S2– c. Br– d. Cr3+
Problem 58b
Determine the number of protons and the number of electrons in each ion. b. Se2-
Problem 58c
Determine the number of protons and the number of electrons in each ion. c. Ga3+
Problem 58d
Determine the number of protons and the number of electrons in each ion. d. Sr2+
Problem 60a,b,d
Predict the charge of the ion formed by each element. a. Mg b. N d. Na
Problem 62
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 64
Write the symbol for each element and classify it as a metal, nonmetal, or metalloid. a. gold b. fluorine c. sodium d. tin e. argon
Problem 65
Determine whether or not each element is a main-group element. a. tellurium b. potassium c. vanadium d. manganese
Problem 66
Determine whether or not each element is a transition element. a. Cr b. Br c. Mo d. Cs
Problem 68
Classify each element as an alkali metal, alkaline earth metal, halogen, or noble gas. a. F b. Sr c. K d. Ne e. At
