Question

2 Name the compounds containing only these elements:
a sodium and fluorine b fluorine and hydrogen
csulfur and hydrogen d bromine and beryllium
3 Why does silica have the formula Si0,7​

Answer 1

compound containing only sodium and fluorine : NaF

compound containing only fluorine and hydrogen:HF

compounds containing only sulphur and hydrogen:H2S

compound containing only Bromine and beryllium :BeBr2

All four points (or oxygen atoms) of the SiO4 structure (which is in a tetrahedron shape) are shared with other SiO4 tetrahedrons in the most common crystalline forms of silica, so even though you can see a SiO4 tetrahedron in the crystal, it is not isolated but connected to other SiO4 tetrahedrons by sharing oxygen atoms. The net chemical formula is SiO2 because of the proportionate proportions of silicon and oxygen in the crystalline structure.

Answer 2

• As we know that Hydrogen fluoride (HF) is a compound that contains fluorine and hydrogen elements.

• Sodium fluoride (NaF) is a compound that contains only sodium and fluorine elements.

• Hydrogen sulfide (H2S) compound contains sulfur and hydrogen elements.

• Beryllium dibromide (BeBr2) compound has bromine and beryllium elements.