Scientists digging in a cave found an unknown substance. The scientists found that the substance’s molecules were moving around each other. The scientists
increased the speed of the substance’s molecules and caused a phase change. How
did the scientists do this, and how did this affect the substance?

By adding heat energy

It became a gas

Explanation:

The molecules moving about another is a clear indicator that the substance is a liquid.

In a liquid, the molecules stick together and move about one another.

When the scientist increase the speed of the of substance, the kinetic energy increases. if this increase causes a phase change, then the substance becomes a gas. So, by adding heat energy a substance becomes gaseous if it is a liquid already.

the catch is that the top numbers are atomic masses the bottom numbers are the numbers of protons and electrons in an uncharged atom. they are the number of that atoms as you would find them on the periodic table. further, the numbers on the left are used to determine the missing numbers on the right

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer

The answer is 65.3312