A Level Chemistry: Atomic structure, questions with answers

Why is the first ionisation energy of sulfur lower than that of phosphorus?

1. Sulfur is more electronegative than phosphorus.
2. Sulfur forms anions more readily.
3. In sulfur, the electron lost is paired with another electron.
4. The sulfur atom is larger than the phosphorus atom.

Which statement about a 3p orbital is correct?

1. It can hold a maximum of six electrons.
2. It has the highest energy of the orbitals with principal quantum number 3.
3. It is at a higher energy level than a 3s orbital but has the same shape.
4. It is occupied by one electron in an isolated phosphorus atom.

Which statement about ¹³¹₅₃I is correct?

1. A negative ion of ¹³¹₅₃I contains 53 neutrons and 52 electrons.
2. A negative ion of ¹³¹₅₃I contains 53 neutrons and 54 electrons.
3. A negative ion of ¹³¹₅₃I contains 78 neutrons and 52 electrons.
4. A negative ion of ¹³¹₅₃I contains 78 neutrons and 54 electrons.

Sodium azide, NaN3, is an explosive used to inflate airbags in cars when they crash. It consists of positive sodium ions and negative azide ions. What are the numbers of electrons in the sodium ion and the azide ion (N3⁻)?

1. sodium ion = 10, azide ion = 20
2. sodium ion = 10, azide ion = 22
3. sodium ion = 12, azide ion = 20
4. sodium ion = 12, azide ion = 22

Which statement about the electrons in a ground state carbon atom is correct?

1. Electrons are present in four different energy levels.
2. There are more electrons in p orbitals than there are in s orbitals.
3. The occupied orbital of highest energy is spherical.
4. The occupied orbital of lowest energy is spherical.

Why is the first ionisation energy of oxygen less than that of nitrogen?

1. The nitrogen atom has its outer electron in a different subshell.
2. The nuclear charge on the oxygen atom is greater than that on the nitrogen atom.
3. The oxygen atom has a pair of electrons in one p orbital that repel one another.
4. There is more shielding in an oxygen atom.