What is the full answer to this problem 39.37/0.90

As you move from right to left on the periodic table the atomic radius fill in the blank

Melting and boiling are endothermic processes. this means that these processes absorb energy from their surroundings in order to occur. use this information and the data you collected in the phase change gizmo to describe what happens to the temperature of water when you boil it, then explain why this result occurs.

How are isotopes of the same chemical element alike? how are they different?