Why do covalent compounds have significantly lower melting/boiling points than ionic compounds?

Which compound most likely has the greatest bond energy?

What is the source of continuous heat and energy that we receive from the sun

Pinene is an unsaturated hydrocarbon found in pine resin. if pinene has m+ = 136 and contains 1 double bond(s) and 2 ring(s); what is its molecular formula? enter the formula in the form ch first, then all other atoms in alphabetical order; do not use subscripts. the formula is case-sensitive