test revision

Question 1

State one difference in the physical properties of the isotopes 63Cu and 65Cu and explain why their chemical properties are the same.

Answer 1

Physical properties: state difference and compare both.
Eg. th boiling point. x has a higher boiling point than y.
Chemical properties: same (nº of electrons)

Question 2

Describe the emission spectrum of hydrogen [2]

Answer 2

1. Lines that show only certain lines/frquencies

2. They converge at high energy levels/frecuency

Question 3

Explain the general increasing trend in the first ionization energies of the period 3 elements, Na to Ar. [2]

Answer 3

1. There is an increasing nº of protons/nuclear charge.
2. Therefore, the atomic radius dicreases.
   Greater energy is needed to overcome increasing atraction between nucleus and electrons

Question 4

Explain why the general melting points of the group 1 metals (Li –> Cs) decrease down the group

Answer 4

Atomic radius increases

The force of atraction between metal ions and delocalized electron dicreases.