Elements and Compounds are ______ substances.
Impure
Pure
Hetrogenous
Mixed
_______ emit radiations which may be harmful.
Noble Gases
Radio active elements
Metals
Non metals
________ of elements is the whole number in which atoms of different elements combines to form a molecule of a compound.
Valency
Atomicity
Ionicity
Molecularity
_______ represents the element hydrogen.
N
O
H
I
________ are inert gases.
Non - metals
Metalloids
Molecules formed from smaller particles are called
Atoms
Ions
Elements
Compounds
A non - metal which is a good conductor of heat and electricity is
Graphite
Chlorine
Oxygen
Phosphorous
_______ do not react chemically with other elements or compounds.
The number of atoms of an element that can join together to form a molecule of that element is known
Radio activity
Ionisation
Attractivity
_______ are substances that cannot be separated into simpler substances.
Mixtures
Solutions