Which of the following metal ions would NOT cause heavy metal pollution if released in high concentrations? (A) Copper (B) Lead (C) Mercury (D) Sodium - HSC - SSCE Chemistry - Question 2 - 2016 - Paper 1

To determine which metal ion would not contribute to heavy metal pollution, we analyze the possible options:

1. Copper (Cu): While copper is an essential element in trace amounts, high concentrations can be toxic and cause pollution.

2. Lead (Pb): Lead is a well-known heavy metal that poses significant environmental and health risks; its presence even in small quantities can lead to severe pollution.

3. Mercury (Hg): Mercury is highly toxic and can accumulate in living organisms, causing heavy metal contamination in the environment.

4. Sodium (Na): Sodium is not classified as a heavy metal. While excessive sodium can affect certain environments, it does not pose the same level of pollution concern as the other three metals listed.

Based on this analysis, the metal ion that would NOT cause heavy metal pollution when released in high concentrations is (D) Sodium.