'Heavy' hydrogen (the isotope deuterium) , 2/1H is involved ,
[2= mass number, 1= atomic (proton) number]
2/1H + 2/1H → 3/2He + 1/0n
The answer will be B) MgCl2 because magnesium has 2 valence electrons and is a metal and chlorine has the atomic number of 17 and is a metal and in order to form an ionic compound, you must have 1 metal and 1 nonmetal
The part of speech that belongs to heat is a noun