What is the difference between `2H` and `H_(2)` ?

What is the difference between H_2 and 2H ?

Write the difference between C and H.

At 25^@C What is the difference between DeltaH and DeltaS for the following reaction? 2H_2(g)+O_2(g)rarr 2H_2O(l)

What is the difference between the following two reactions ? (a) Mg + 2HCl to MgCl_(2) + H_(2) (b) NaOH + HCl to NaCl + H_(2)O .

What is the difference between the number of carbon atoms and hydrogen atoms in C_2H_6 and C_3H_8

The range R of projectile is same when its maximum heights are h_(1) and h_(2) . What is the relation between R, h_(1) and h_(2) ?

What is the difference between the following two types of reactions? AgNO_(3)+HCl toAgCl+HNO_(3) Mg+2HCl toMgCl_(2)+H_(2)