Which ones are physical change and which ones are chemical reactions: Evaporation, condensation, melting, combustion, neutralization

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

How far is the region from the equator or control climate

Calculate the ratio of h+ ions to oh– ions at a ph = 7. find the concentration of h+ ions to oh– ions listed in table b of your student guide. then divide the h+ concentration by the oh– concentration. record this calculated ratio in table a of your student guide. compare your approximated and calculated ratios of h+ ions to oh– ions at a ph = 7. are they the same? why or why not? record your comparison in table a. what is the concentration of h+ ions at a ph = 7? mol/l what is the concentration of oh– ions at a ph = 7? mol/l what is the ratio of h+ ions to oh– ions at a ph = 7? : 1