In a calorimetry lab, sodium oxide is combined with water. Compute the heat released in the formation of 1.99 grams of sodium hydroxide. Na2O +
H2O -> 2NaOH + 215. 76 kJ

Yes, endothermic means it turns cold. and some chemical changes include change of tempature.

Elements would be the right answer

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.