For each example of a phase change, identify whether heat is absorbed from the surroundings or
released into the surroundings.
a popsicle melts on a hot day.
rubbing alcohol evaporates from the surface of the skin.
lava solidifies when it erupts from a volcano.

In case of popsicle and alcohol, heat is absorbed from the surrounding.

In case of lava heat is emitted into the surrounding.

Melting of popsicle is just a change of state from solid to liquid. This is the phenomenon which occurs when the popsicle gets the heat from the surrounding and it absorbs the heat, thereby turning into liquid. So it absorbs heat from the surrounding.

The alcohol when spread on the skin evaporates into vapour. This is the phenomenon of evaporation which occurs when alcohol absorbs heat from the surrounding and thereby turning into vapour.

Similarly, when lava solidifies into solid, the change of state occurs. As lava emits heat into the surrounding, the temperature of the lava goes down, thereby changing it into solid. So it emits heat into surrounding.

give me abc and i will get it for u.

the formula mass of a molecule or a compound is the sum of the atomic weights of the atoms in its empirical formula

(that's what i know about formula mass)