How many total atoms of each element are presented in the following formula ​

u should know their p and e

then u may able to answer

Aluminium (Al): (3*2)+(5*2)=16

Sulphor (S): (3*1)=3

Oxygen (O): (4*3)+(3*1)=15

law of conservation of matter

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.