Question

Select the metal which is hardest among the following:

• A. silver
• B. gold
• C. platinum
• D. aluminium

Answer 1

Answer: (C)

platinum

As the size of the metal increases, they become harder.

So, size of the metals- $Al<Ag<Au<Pt$

As we move across the period size decreases hence $Pt>Au$.

$\therefore$ $Pt$ is hardest.