Chemistry
Explain the term – 'atomicity'. Give a reason why –
(a) Helium is considered monoatomic, but hydrogen a diatomic molecule.
(b) Ozone is considered triatomic, but phosphorus a tetratomic molecule.
Answer
Atomicity — It is the number of atoms present in a molecule of an element.
(a) Helium (He) is considered monoatomic because it contains only one atom of helium while hydrogen contains two atom of hydrogen (H2) therefore it is considered a diatomic molecule.
(b) Ozone is considered triatomic because it is composed of three atoms of Oxygen (O3) while phosphorous is composed of four atoms (P4), therefore, it is considered a tetratomic molecule.
Related Questions
State the main points of contradiction of Dalton’s atomic theory by the Modern Atomic Theory.
Atoms of the same element or different elements combine to form a molecule. Give two examples each of –
(a) atoms of the same element
(b) atoms of different elements combining to form a molecule.
State the atomicity of the following:
(a) Neon
(b) Oxygen
(c) Chlorine
(d) Argon
(e) Sulphur
'A radical takes part — unsplit in a chemical reaction and retains its identity in reactions'. With reference to the radical:
(a) ammonium
(b) bisulphate
(c) carbonate — state the group of atoms present in each radical.