How many basic forces are there in the universe?

Four basic fources.

Explanation:

Fundamental force, also called fundamental interaction, in physics, any of the four basic forces—gravitational, electromagnetic, strong, and weak—that govern how objects or particles interact and how certain particles decay. All the known forces of nature can be traced to these fundamental forces.

graph slopes whilst gas cools, then it is flat whilst conensation to liquid happens, the coolong liquid then graphs as a slope when it solidifies graph is flat

latent heat