A scientist measures the standard enthalpy change for the following reaction to be -574.3 kJ: H2CO(g) O2(g)CO2(g) H2O(l) Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of H2O(l) is

Nonmetals usually react by gaining electrons

Van der waals forces are temporary electromagnetic forces established between uncharged atoms. some neutral molecules, when close together, can become temporarily “charged,” as electrons move around the atom. water is a polar molecule, the side of the molecule that the hydrogens bond to being more positive, and the opposite side bound to the lone pairs of electrons being more negative. this means that it participates in dipole-dipole interaction (non-polar exhibits dispersion forces), and it has the capacity for hydrogen bonding.

The independent is what is changed, the dependent is was is measured or the reaction.

I'd say your answer would be the sides of a metal pan become hot when the pan is placed on the stove burner