water H2O is a molecule made of oxygen and hydrogen. The bonds that hold water molecules together are due to share ___, and known as covalent bonds.

Check the correct box to describe the periodic trends in electronegativity. electronegativity across a period: decreases. increases. electronegativity down a group: decreases. increases.

Tell me the iupac names of the following alcohols:

How many atoms or molecules are there in a mole of a substance?