Chapter 3 – Practice Problem Solutions – Odd Answers
- List the three statements that make up the modern atomic theory.
All matter is composed of atoms; atoms of the same element are the same, and atoms of different elements are different; atoms combine in whole-number ratios to form compounds.
- Explain how atoms are composed.
- Which is larger, a proton or an electron?
A proton is larger than an electron. - Which is larger, a neutron or an electron?
- What are the charges for each of the three subatomic particles?
Proton: 1+; Electron: 1−; Neutron: 0 - Where is most of the mass of an atom located?
- Sketch a diagram of a boron atom, which has five protons and six neutrons in its nucleus.
- Sketch a diagram of a helium atom, which has two protons and two neutrons in its nucleus.
- Define atomic number. What is the atomic number for a boron atom?
The atomic number is the number of protons in a nucleus; Boron has an atomic number of five. - What is the atomic number of helium?
- Define isotope and give an example.
Isotopes are atoms of the same element but with different numbers of neutrons, [latex]\ce{^{1}_{1}H}[/latex] and [latex]\ce{^{2}_{1}H}[/latex] are examples. - What is the difference between deuterium and tritium?
- Which pair represents isotopes?
- a. [latex]\ce{^{4}_{2}He}[/latex] and [latex]\ce{^{3}_{2}He}[/latex]
- b. [latex]\ce{^{56}_{26}Fe}[/latex] and [latex]\ce{^{56}_{25}Mn}[/latex]
- c. [latex]\ce{^{24}_{14}He}[/latex] and [latex]\ce{^{31}_{15}P}[/latex]
- Which pair represents isotopes?
- a. [latex]\ce{^{40}_{20}Ca}[/latex] and [latex]\ce{^{40}_{19}K}[/latex]
- b. [latex]\ce{^{56}_{26}Fe}[/latex] and [latex]\ce{^{56}_{28}Fe}[/latex]
- c. [latex]\ce{^{238}_{92}He}[/latex] and [latex]\ce{^{235}_{92}U}[/latex]
- Give complete symbols of each atom, including the atomic number and the mass number.
- a. An oxygen atom with 8 protons and 8 neutrons
- b. A potassium atom with 19 protons and 20 neutrons
- c. A lithium atom with 3 protons and 4 neutrons
- Give complete symbols of each atom, including the atomic number and the mass number.
- a. A magnesium atom with 12 protons and 12 neutrons
- b. A magnesium atom with 12 protons and 13 neutrons
- c. A xenon atom with 54 protons and 77 neutrons
- Americium-241 is an isotope used in smoke detectors. What is the complete symbol for this isotope?
- Carbon-14 is an isotope used to perform radioactive dating tests on previously living material. What is the complete symbol for this isotope?
- Give atomic symbols for each element.
- a. sodium
- b. argon
- c. nitrogen
- d. radon
- Give atomic symbols for each element.
- a. silver
- b. gold
- c. mercury
- d. iodine
- Give the name of the element.
- a. Si
- b. Mn
- c. Fe
- d. Cr
- Give the name of the element.
- a. F
- b. Cl
- c. Br
- d. I
