Which of the following metals will give hydrogen with dilute hydrochloric acid ?
Fe, Cu, Mg

Explanation

To determine which metals will give hydrogen with dilute hydrochloric acid (HCl), we need to refer to the reactivity series of metals. The reactivity series is a list of metals arranged in order of decreasing reactivity.

### Step-by-Step Solution:

1. **Identify the Metals**: The metals given in the question are Iron (Fe), Copper (Cu), and Magnesium (Mg).

2. **Understand the Reactivity Series**: The reactivity series indicates how metals react with acids. Metals that are more reactive than hydrogen can displace hydrogen from acids, while those that are less reactive cannot.

...