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## The atom

Exercise 4.6

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

Solution not yet available

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.

1. False. They both have $$\text{10}$$ protons and $$\text{10}$$ electrons, but $$_{10}^{20}\text{Ne}$$ has $$\text{10}$$ neutrons and $$_{10}^{22}\text{Ne}$$ has $$\text{12}$$ neutrons.

2. True.
3. True.
4. False. Group $$\text{1}$$ elements readily form positive 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

Solution not yet available

The charge of an atom is:

1. positive

2. neutral

3. negative

4. none of the above

Solution not yet available

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

Solution not yet available

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

1. The element has the same electron configuration as $$_{92}^{238}\text{U}$$

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. $$1\text{s}^{2}2\text{s}^{2}2\text{p}^{5}$$

Solution not yet available

Give the standard notation for the following elements:

1. beryllium

2. carbon–12

3. titanium–48

4. fluorine

1. Beryllium has $$\text{4}$$ protons and $$\text{5}$$ neutrons. So the number of nucleons is $$\text{9}$$. The standard notation is: $$_{4}^{9}\text{Be}$$

2. Carbon has $$\text{6}$$ protons and $$\text{6}$$ neutrons. So the number of nucleons is $$\text{12}$$. The standard notation is: $$_{6}^{12}\text{C}$$

3. Titanium has $$\text{22}$$ protons and $$\text{26}$$ neutrons. So the number of nucleons is $$\text{48}$$. The standard notation is: $$_{22}^{48}\text{Ti}$$

4. Fluorine has $$\text{9}$$ protons and $$\text{10}$$ neutrons. So the number of nucleons is $$\text{19}$$. The standard notation is: $$_{9}^{19}\text{F}$$

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

1. aluminium

2. phosphorus

3. carbon

4. oxygen ion

5. calcium ion

Solution not yet available

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. $$_{5}^{11}\text{B}$$

Solution not yet available

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. $$_{4}^{x}\text{Be}$$

Solution not yet available

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

1. $$_{25}^{12}\text{Mg}$$

2. $$_{12}^{26}\text{Mg}$$

3. $$_{13}^{24}\text{Al}$$

Solution not yet available

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.

Solution not yet available

Complete the following table:

 Element or ion Electron configuration Core electrons Valence electrons Boron ($$\text{B}$$) Calcium ($$\text{Ca}$$) Silicon ($$\text{Si}$$) Lithium ion ($$\text{Li}^{+}$$) Neon ($$\text{Ne}$$)
Solution not yet available