Atomicity is a simple but frequently tested concept in Class 9 Chemistry (Atoms and Molecules chapter).
Atomicity: Number of atoms in one molecule.
Diatomic: H₂, O₂, N₂ (atomicity = 2).
Triatomic: O₃ Ozone (atomicity = 3).
Polyatomic: P₄ (4), S₈ (8).
Atomicity is defined as the total number of atoms present in one molecule of an element or compound.
In simple terms: count how many atoms are bonded together to form one molecule of the substance.
| Molecule | Atomicity | Name |
|---|---|---|
| Noble gases (He, Ne, Ar) | 1 | Monoatomic |
| H₂, O₂, N₂, Cl₂, F₂ | 2 | Diatomic |
| O₃ (Ozone) | 3 | Triatomic |
| P₄ (Phosphorus) | 4 | Tetraatomic |
| S₈ (Sulphur) | 8 | Polyatomic |
Most asked in exams:
Atomicity is the number of atoms present in one molecule of an element. Examples: H₂ has atomicity 2 (diatomic), O₃ (ozone) has atomicity 3 (triatomic), P₄ has atomicity 4, and S₈ has atomicity 8 (polyatomic).
BPT Full Form
BPT full form is Bachelor of Physiotherapy. 4.5-year undergraduate course. Eligibility: 10+2 with PCB, 50% marks. Career: hospitals, sports, clinics. India physiotherapy course details.
British Ruled India for How Many Years?
British ruled India for approximately 190 years (1757–1947). Battle of Plassey 1757 marked British dominance. India gained independence on 15 August 1947. Full timeline.
BRO Full Form — Border Roads Organisation of India
BRO stands for Border Roads Organisation — established 1960 to build roads in border areas of India. Motto: Shramena Sarvam Sadhyam. Under Ministry of Defence.
BSNL Full Form: Bharat Sanchar Nigam Limited
BSNL stands for Bharat Sanchar Nigam Limited, India's government-owned telecom company formed in 2000. It provides mobile, broadband, and landline services across India.
Bua in English — What Is Bua Called in English?
Bua (बुआ) in English means Paternal Aunt — your father's sister. Bua's husband is called Fufaji. Hindi kinship terms explained.
Turn this guide into revision flashcards, a practice exam, or an AI-generated podcast — free, no signup required.