End of chapter exercises

Write down only the word/term for each of the following descriptions.

1. The sum of the number of protons and neutrons in an atom

2. The defined space around an atom's nucleus, where an electron is most likely to be found

For each of the following, say whether the statement is true or false. If it is false, re-write the statement correctly.

1. \(_{10}^{20}\text{Ne}\) and \(_{10}^{22}\text{Ne}\) each have 10 protons, 12 electrons and 12 neutrons.

2. The atomic mass of any atom of a particular element is always the same.

3. It is safer to use helium gas rather than hydrogen gas in balloons.

4. Group 1 elements readily form negative ions.

The three basic components of an atom are:

1. protons, neutrons, and ions

2. protons, neutrons, and electrons

3. protons, neutrinos, and ions

4. protium, deuterium, and tritium

The charge of an atom is:

1. positive

2. neutral

3. negative

4. none of the above

If Rutherford had used neutrons instead of alpha particles in his scattering experiment, the neutrons would:

1. not deflect because they have no charge

2. have deflected more often

3. have been attracted to the nucleus easily

4. have given the same results

Consider the isotope \(_{92}^{234}\text{U}\). Which of the following statements is true?

1. The element is an isotope of \(_{94}^{234}\text{Pu}\)

2. The element contains 234 neutrons

3. The element has the same electron configuration as \(_{92}^{238}\text{U}\)

4. The element has an atomic mass number of 92

The electron configuration of an atom of chlorine can be represented using the following notation:

1. \(1\text{s}^{2}2\text{s}^{8}3\text{s}^{7}\)

2. \(1\text{s}^{2}2\text{s}^{2}2\text{p}^{6}3\text{s}^{2}3\text{p}^{5}\)

3. \(1\text{s}^{2}2\text{s}^{2}2\text{p}^{6}3\text{s}^{2}3\text{p}^{6}\)

4. \(1\text{s}^{2}2\text{s}^{2}2\text{p}^{5}\)

Give the standard notation for the following elements:

1. beryllium

2. carbon–12

3. titanium–48

4. fluorine

Give the electron configurations and Aufbau diagrams for the following elements:

1. aluminium

2. phosphorus

3. carbon

4. oxygen ion

5. calcium ion

For each of the following elements give the number of protons, neutrons and electrons in the element:

1. \(_{78}^{195}\text{Pt}\)

2. \(_{18}^{40}\text{Ar}\)

3. \(_{27}^{59}\text{Co}\)

4. \(_{3}^{7}\text{Li}\)

5. \(_{5}^{11}\text{B}\)

For each of the following elements give the element or number represented by x:

1. \(_{45}^{103}\text{X}\)

2. \(_{x}^{35}\text{Cl}\)

3. \(_{4}^{x}\text{Be}\)

Which of the following are isotopes of \(_{12}^{24}\text{Mg}\):

1. \(_{25}^{12}\text{Mg}\)

2. \(_{12}^{26}\text{Mg}\)

3. \(_{13}^{24}\text{Al}\)

If a sample contains \(\text{69}\%\) of copper–63 and \(\text{31}\%\) of copper–65, calculate the relative atomic mass of an atom in that sample.

Complete the following table: