Only 2 questions me

1. which reaction substitutes one element in a reactant with another to form a product?

single-displacement

combustion

synthesis

double-displacement

2.which choice correctly describes the subatomic particles in the isotope 28mg?

28 protons, 12 electrons, 28 neutrons

12 protons, 12 electrons, 16 neutrons

12 protons, 12 electrons, 12 neutrons

12 protons, 16 electrons, 28 neutrons

is there multiple choice answers?

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.