If an objects mechanical energy is equal to its potential energy how much kinetic energy does it have explain

Which of these will change if the air in aclosed bottle is heated? abcdthe mass of the airthe composition of the airthe air pressure in the bottlethe number of air molecules in the bottle

The name of the ion, s2-, is: sulfurous ion sulfide ion sulfur ion sulfate ion

How many atoms are there in 5.70 mol of mg