Molecules and compound

Compound: Substances that have two or more elements chemically joined together
Water has hygrogen atoms and oxygen atom chemically joined together, so it is a coumpound.

Molecules: Substances that have one or more elements joined together by covalent bond
eg. Bromine Br-Br
Water H-O-H

Therefore, water is compound and also molecule.

(There are different forms of compound, molecule is one form of them.)

Molecules 係只element同element 有bonding 好似水咁h2o 係只 一個 oxgen同二個
hydrogen 大家share electron. 而molecule 有自己既特性. 好似 element F 佢本身
係好有很強既毒性和付食性. 但F2Ca 係牙膏既成份.
但compound 只係幾種element 或molecules撈在一起
但一會影響本身既特性