What types of change if any can reach equilibrium

a chemical change only
a physical change only
both
neither

Each pair of clay balls represents to planetesimals if each plane test molluscum pound of the same material and is separated by the same distance which pair experiences the greatest gravitational attraction

If an area has high air pressure and low humidity, what type of weather will it most likely have? plz !

Use the periodic table to complete this equation that represents nuclear fission processesun - ba c 3 n