Determination of electrical conductivity:

relationship between the electrical conductivity and the type of intermolecular force of attraction existing between the molecules

Metals include elements such as, iron, copper, chromium, titatium, etc., I'm sure you know what a metal and non-metal is by looking at your periodic table.

melting is breaking the bonds in the crystals. Thus, what does that mean? The stronger the bonds are, the harder to break and therefore the higher the melting point.

"the periodic table is arranged in order of atomic number."

geosphere and hydrosphere.

this is because the geosphere has to do with geological events, while the hydrosphere controls all water on earth.