Calculate the force of earth's gravity on a 1kg mass at earth's surface. the mass of the earth is 6.0

Force of earth gravity on 1 kg mass is 9.8 N.

Since the mass is at earth surface, therefore its distance from the centre of earth is equal to the radius of the earth i.e. 6400 km.

The force of earth gravity is calculated as

F=GMm/r^2 =(6.67*〖10〗^(-11)*6*〖10〗^24*1)/〖(64*〖10〗^6)〗^2 =9.8 N

freezing

deposition

condensation

explanation;

melting also called fusion is the process where solid becomes liquid, sublimation is the process where solid becomes gaseous without first changing to liquid, deposition involves change from gaseous to solid state, freezing involves change from liquid to solid, boiling or evaporation involves change of liquid to gaseous state, while condensation is the change from gaseous state to liquid state.

endothermic reactions involves absorption of heat from the surroundings or the environment while exothermic reactions involves loss of heat energy to the surroundings.

in this case, sublimation, evaporation and melting are endothermic reactions (gain energy from the environment) while, freezing, deposition and condensation are exothermic (loss of energy to the surroundings) reactions.

pe = weightxheight = 2000x1000=2,000,000joules