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Problem 22d
Determine whether each of the following statements is true or false. If false, correct the statement to make it true: (d) The protons in the nucleus of the helium atom are held together by a force called the strong nuclear force.
Problem 23a
Consider an atom of 10B. (a) How many protons, neutrons, and electrons does this atom contain?
Problem 23b
Consider an atom of 10B. (b) What is the symbol of the atom obtained by adding one proton to 10B?
Problem 23c
Consider an atom of 10B. (c) What is the symbol of the atom obtained by adding one neutron to 10B?
Problem 23d
Consider an atom of 10B. (d) Are either of the atoms obtained in parts (b) and (c) isotopes of 10B? If so which one?
Problem 24a
Consider an atom of 63Cu. (a) How many protons, neutrons, and electrons does this atom contain?
Problem 24b
Consider an atom of 58Ni. (b) What is the symbol of the ion obtained by removing two electrons from 58Ni?
Problem 24c
Consider an atom of 63Cu. (c) What is the symbol for the isotope of 63Cu that possesses 36 neutrons?
Problem 25a
(a) Define atomic number and mass number.
Problem 25b
(b) Which of these can vary without changing the identity of the element?
Problem 26a
(a) Which two of the following are isotopes of the same element: 3116X, 3115X, 3216X?
Problem 26b
(b) What is the identity of the element whose isotopes you have selected?
Problem 27a,b,c
How many protons, neutrons, and electrons are in the following atoms? (a) 84Kr (b) 200Hg (c) 70Ga
Problem 27d
How many protons, neutrons, and electrons are in the following atoms? (d) 80Br
Problem 27e,f
How many protons, neutrons, and electrons are in the following atoms? (e) 184W (f) 181Ta.
- Each of the following isotopes is used in medicine. Indicate the number of protons and neutrons in each isotope: (a) samarium-153 (b) lutetium-177 (c) bismuth-213 (d) molybdenum-99 (e) lead-212 (f) caesium-131.
Problem 28
Problem 29c
Fill in the gaps in the following table, assuming each column represents a neutral atom.
Symbol 79Br
Protons 25 82
Neutrons 30 64
Electrons 48 86
Mass no. 222 207
Complete the third row of the table.
Problem 29d
Fill in the gaps in the following table, assuming each column represents a neutral atom.
Symbol 79Br
Protons 25 82
Neutrons 30 64
Electrons 48 86
Mass no. 222 207
Complete the fourth row of the table.
Problem 29e
Fill in the gaps in the following table, assuming each column represents a neutral atom.
Symbol 79Br
Protons 25 82
Neutrons 30 64
Electrons 48 86
Mass no. 222 207
Complete the fifth row of the table.
Problem 30a
Fill in the gaps in the following table, assuming each column represents a neutral atom.
Symbol 112Cd
Protons 38 92
Neutrons 58 49
Electrons 38 36
Mass no. 81 235
Complete the first row of the table.
Problem 30b
Fill in the gaps in the following table, assuming each column represents a neutral atom.
Symbol 112Cd
Protons 38 92
Neutrons 58 49
Electrons 38 36
Mass no. 81 235
Complete the second row of the table.
Problem 31a
Write the correct symbol, with both superscript and subscript, for each of the following. Use the list of elements in the front inside cover as needed: (a) the isotope of platinum that contains 118 neutrons
Problem 31b,c
Write the correct symbol, with both superscript and subscript, for each of the following. Use the list of elements in the front inside cover as needed: (b) the isotope of krypton with mass number 84 (c) the isotope of rhenium with mass number 187
Problem 31d
Write the correct symbol, with both superscript and subscript, for each of the following. Use the list of elements in the front inside cover as needed: (d) the isotope of magnesium that has an equal number of protons and neutrons.
- Without doing any detailed calculations (but using a periodic table to give atomic weights), rank the following samples in order of increasing numbers of atoms: 0.2 mol PCl5 molecules, 80 g Fe2O3, 3.0 3 1023 CO molecules.
Problem 32
Problem 33a
(a) What isotope is used as the standard in establishing the atomic mass scale?
Problem 33b
(b) The atomic weight of boron is reported as 10.81, yet no atom of boron has the mass of 10.81 u. Explain.
Problem 34a
(a) What is the mass in u of a carbon-12 atom?
Problem 35
Only two isotopes of copper occur naturally: 63Cu (atomic mass = 62.9296 amu; abundance 69.17%) 65Cu (atomic mass = 64.9278 amu; abundance 30.83%). Calculate the atomic weight (average atomic mass) of copper.
Problem 36
Rubidium has two naturally occurring isotopes, rubidium-85 (atomic mass = 84.9118 amu; abundance = 72.15%) and rubidium-87 (atomic mass = 86.9092 amu; abundance = 27.85%). Calculate the atomic weight of rubidium