Due to heat , the kinetic energy of the atoms in the substance increases due to which they start vibrating vigorously and the inter-molecular attraction decreases and the substance increases in volume. For example, on boiling water...heat energy imparted makes the volume increase and finally turn into steam or water vapour in air.(The inter-molecular space in air is more than that in water.)
Ba3PO4 is not neutral, it is positive. (NH4)2SO4 is neutral, the charges cancel.
Mg2OH is not neutral, it is positive. LiF2 is not neutral, it is negative. CaOH is not neutral, it is positive. The answer is (NH4)2SO4, correct ions will have a neutral charge.
Both liquids and gasses are fluids is the answer
a) 6 electrons - because atomic number is the same as the electron number
b) 4 - because 6-2=4
c) Covalent bonds - it needs 4 more electrons for a full outer shell.
