Glass is often said to be a supercooled liquid.

Glass has no definite melting point.

Soda glass is harder than pyrex glass.

Boron is present in pyrex glass.

Both boiling and evaporation are surface phenomena.

Boiling is a surface phenomenon, but evaporation is a bulk phenomenon.

Both boiling and evaporation are bulk phenomena.

Boiling is a bulk phenomenon, but evaporation is a surface phenomenon.

Diamond has a tetrahedral structure, whereas graphite has a hexagonal planar structure.

Both physical and chemical properties of diamond and graphite are different.

Graphite is soft, but diamond is hard.

Graphite is a good conductor of electricity, while diamond is not.

lime, silica and sulphur dioxide

lime, silica and carbon dioxide

lime, silica and alumina

lime, silica and boric acid