Answer : The balanced chemical equation is,

Explanation :
Balanced chemical equation : It is defined as the number of atoms of individual elements present on the reactant side must be equal to the number of atoms of individual elements present on product side.
The given unbalanced chemical reaction is,

This chemical reaction is an unbalanced reaction because in this reaction, the number of atoms of individual elements are not balanced.
In order to balanced the chemical reaction, the coefficient 2 is put before the
, the coefficient 3 is put before the
and the coefficient 4 is put before the
.
The energy evolved in this reaction = 
Thus, the balanced chemical reaction will be,

To calculate the mass of milk of magnesia given, we need certain data like molar mass of the compound which needs the atomic mass of the atoms in the compound. We calculate as follows:
Molar mass of <span>Mg(OH)2 = 24.3 g/mol + (2 x (16 + 1.0)) = 58.30 g/mol
Mass = 3.2 mol (</span>58.30 g/mol) = 186.56 grams
Im pretty sure it nitric acid
Alpha decay involves the loss of an alpha particle, aka a helium nucleus. This results in the mass number of the original element decreasing by 4 and the atomic number decreasing by 2. Assuming 23942u is uranium (92), the resulting element's atomic number is 90, making it thorium.
Answer: C
Explanation: Took the test