Question

The total number of atoms that exists in Nitric acid is ____________ that combine together in a fixed proportion.
1. 4
2. 5
3. 6
4. 8

Answer 1

Correct Answer - Option 2 : 5

The correct answer is Option(2).i.e.5. 

• The total number of atoms that exist in Nitric acid is five.
• Nitric acid (HNO₃) - Hydrogen-1, Nitrogen-1, Oxygen-3. (1+1+3)=5. 
• Molecules of Compounds: 
  • Atoms of various elements that combine together in a fixed proportion are called compound molecules.
  • For example, Ammonia (NH₃) comprises three atoms of hydrogen and one atom of Nitrogen. 
• Molecule: 
  • It is the collection of various atoms that chemically combine with each other.
  • Through certain forces of attraction, atoms of same or different elements, are bound together to form molecules.
  • Therefore, the smallest particle of a substance is the molecule which can exist independently. 
• Molecules of Elements : 
  • Through combinations of similar types of atoms, the molecules of an element are created.
  • For example, Oxygen is made up of two atoms whereas helium (He) is made up of only one atom. ​
• Atom: 
  • An atom is the smallest invisible unit of matter that constitutes a chemical element.
  • Every plasma, solid, gas & liquid, composed of ionized or neutral atoms.
  • Around 100 picometers across, atoms are extremely small.