Chemical Periodicity of Other Elements (CIE A Level Chemistry)

The period 4 elements gallium (Ga), germanium (Ge), arsenic (As) and selenium (Se) are the elements directly below aluminium, silicon, phosphorus and sulfur in the Periodic Table.

The properties of each period 4 element resemble those of the period 3 element directly above it. 

Which period 4 elements form oxides that dissolve in water to give an acid solution?

Elements X and Y react together to form compound Z. Elements X and Y are both in Period 3. Element X has the second smallest atomic radius in Period 3. Apart from argon, there is only one element in Period 3 which has a lower melting point than element Y.

Which compound could be Z?

Compound X readily conducts electricity when added to water to produce a solution but does not conduct electricity in its liquid state.

Which of the following could X be?

1	MgCl2
2	PCl3
3	SiCl4

The successive ionisation energies of elements X and Y are shown below.

Element X
IE	1st	2nd	3rd	4th	5th	6th	7th	8th
IE (kJ mol-1)	590	1145	4912	6491	8153	10496	12270	14206

 

Element Y
IE	1st	2nd	3rd	4th	5th	6th	7th	8th
IE (kJ mol-1)	1012	1907	2914	4964	6274	21267	25431	29872

 

X and Y form ions with the same electron configuration as argon.

What are the identities of elements X and Y respectively?

G and J are oxides of different Period 3 elements.

If one mole of J is added to water, the solution formed is neutralised by exactly one mole of G.

What could be the identities of G and J? 

	G	J
A	Na2O	SO3
B	Na2O	P4O10
C	Al2O3	SO3
D	Al2O3	P4O10

An element Z has the same oxidation state as a common iron ion but the Z ion has the same number of electrons as Ne . An oxide of element Z reacts with a strong acid to produce a chloride salt but does not dissolve in water.

What is the correct identity of element Z?