Please help me find what types of reactions these are !!! ASAPP

In which of these cases are the two wave points considered to be in phase with each other?

What must be in balance for temperatures to remain constant?

Covalent bonds generally form when the bonded elements have a difference in electronegativity less than 1.5. subtract the electronegativities for the following pairs of elements and predict whether they form a covalent bond. electronegativity difference of c and c: ionic covalent electronegativity difference of mg and cl: ionic covalent