A sample of iron has the following isotopic composition by mass.

Calculate the relative atomic mass of iron based on this data, giving your answer to two decimal places.

Calculate the number of electrons in the ion \(^{{\text{56}}}{\text{F}}{{\text{e}}^{2 + }}\).

Describe the bonding in iron and explain the electrical conductivity and malleability of the metal.

\(\frac{{(54 \times 5.95) + (56 \times 91.88) + (57{\text{ }}2.17)}}{{100}}\);

55.90;

Award [2] for correct final answer.

Answer must be to 2 d.p.

24;

metallic (bonding);

positive ions/cations and delocalized/sea of electrons;

electrostatic attraction between the two;

Award [2 max] for description of bonding

Conductivity:

electrons delocalised/free to move;

Malleability:

atoms/ions/cations can move without breaking bonds / atoms/ions/cations can slide

past each other;

Most candidates could correctly calculate the relative atomic mass although a few lost a mark by giving their answers to 1 or 3 decimal places.

Most candidates correctly calculated the number of electrons, but the most frequent incorrect answers were 28 and 54.

The explanation of iron‟s properties was well answered in terms of metallic bonding and most candidates correctly described its electrical conductivity as due to free flowing electrons. However, only a few could explain malleability in terms of the layers of ions being able to slide over each other.