f.4 chemistry

metal oxide?
係呀~
點解~因為~
the melting point of the chemicals depends on the intermolecualr force~
For metal oxide , most of their molecule are held by ionic bond
The strength of the ionic bond is greater than van der waals` force
That`s why a number of non-metal oxides is not in solid state at room temperature
記住~因為金屬氧化物分子之間既力係由離子鍵所產生。
另外~佢既巨大離子結晶結構(ionic crystal structure)都係溶點上升既原因。

I am not so sure. But in the metal oxides I known, all are solid.

no,mercury is liquid state