Question

Which among the following will be the softest metal?
(A) Sodium
(B) Aluminium
(C) Iron
(D) All of the above

Answer 1

Hint: You already know that all elements given in the option are from different groups of periodic tables so their properties can’t be similar. The softest metal among these elements is from the first group.

Complete step by step answer:
Sodium belongs to Group I in the Modern Periodic Table, which consists of Alkali Metals.
All the elements of this group, except Hydrogen, are extremely reactive metals, the reactivity increases as we go down the group.
Alkali metals have large atomic size due to the weak force of attraction between the nucleus and the valence electron. This means that alkali metals quickly lose their only valence electron, hence being more reactive. Since reactivity increases as we go down the group, this also means that the atomic size would be larger.
Sodium has a larger atomic size because of less force of attraction between the valence electron and the nucleus, hence it is soft. You can also find that Potassium is softer than Sodium, Rubidium being softer than Potassium, and this goes on.

Therefore, we can conclude that the correct answer to this question is A.

Note: You should also know that the hardest metal among these options would be Iron. Iron is also one of the most abundant elements found on earth.
Tungsten is one of the hardest metals present on earth. The meaning of the Tungsten itself is ‘ heavy stone’. Moreover, it has the highest melting point, so it gets used in the making of light bulbs.