Matter and Its Composition — CHEMISTRY STD 7 — Question

________ and _______ are pure substances.

Automobile emissions can be checked by installing a device called ___________

List: oxygen, carbonic, suIphur dioxide gas, precipitation, helium
Every nine parts of water by weight contains eight parts by weight of _________.

There is a change in state and _____________ during a chemical change.

A statements that describes a chemical reaction in terms of symbols and ___________ is called a chemical equation

A group of atoms that react as a single unit ______

Oxygen is___________to litmus testing.

In a _______ the substances are not combined chemically.

The basic conditions necessary for a chemical reaction is _______

List: amalgam, chlorine, gallium, sodium chloride, silver chloride
A gas used to sterilisation of drinking water is ________