Identify the terms, like terms, coefficients and constants
2+3a+9a

Like terms in algebra are terms that have the same variables and power. Constants contain only numbers, we call them constants because their values don't change. Coefficients are the numbers in front of the variable ex: 5y in that expression 5 is the coefficient. So in the expression 2+3a+9a there is one constant which is 2 the likes terms are 3a and 9a because they have the same variable. And the coefficients are 3 and 9 because they are in front of the variable.

Like terms :  3a and 9a

Terms: All of them

Coefficients:  3 and 9

Constant : 2

Evaporation: this is when warmth from the sun causes water from oceans, lakes, streams, ice and soils to rise into the air and turn into water vapour (gas). water vapour droplets join together to make clouds! condensation: this is when water vapour in the air cools down and turns back into liquid water.