Will the following reaction occur? Mg + HCI →
o Yes, magnesium will replace hydrogen because a bond between H-Cl is unstable.
Yes, magnesium will replace hydrogen because hydrogen is higher on the activity series
list.
o
o this reaction will not occur
Yes, magnesium will replace hydrogen because magnesium is higher on the activity
series list.
2 3 4 5 6
7
8
9 10 11

Yes, magnesium will replace hydrogen because magnesium is higher on the activity  series list.

Explanation:

A single replacement reaction is one in which a more reactive element displaces a less reactive element from its salt solution.  

A general single displacement reaction can be represented as :

When magnesium is added to hydrochloric acid, magnesium being more reactive than hydrogen displaces hydrogen atom its salt solution and lead to formation of magnesium chloride and hydrogen gas.