Bright Tutorials Bright Tutorials
ICSE Class 7 Chemistry Question 16 of 16

Atomic Structure — Question 5

Back to all questions
5
Question

Question 5

Name the following

  1. A molecule of a compound containing two oxygen atoms and one nitrogen atom.

  2. The radical containing one nitrogen and four hydrogen atoms.

  3. The compound formed when iron [Fe2+] combines with oxygen [O2-].

  4. The group of the Modern Periodic Table to which calcium [Ca2+] belongs.

  5. A non-metal which forms a polyatomic molecule with more than three atoms.

Answer

  1. Nitrogen dioxide [NO2]

  2. Ammonium [NH4]

  3. Iron (II) oxide [FeO]

  4. Group 2

  5. Phosphorous (P4)

ICSE Class VII Chemistry Chapter 3 15 Marks

Atomic Structure — Quick Study Guide

Atoms are the building blocks of all matter. Understanding atomic structure is essential for all of chemistry.

Key Definitions

  • Atom: Smallest particle of an element with its chemical properties
  • Molecule: Group of two or more atoms bonded together
  • Element: Pure substance with only one type of atom
  • Compound: Two or more different elements chemically combined
  • Atomic number (Z): Number of protons = Number of electrons
  • Mass number (A): Protons + Neutrons
  • Valency: Combining capacity of an element
  • Isotopes: Same element, different mass numbers

Electronic Configuration Rules

K shell = max 2 electrons, L shell = max 8, M shell = max 8 (for first 20 elements). Fill inner shells first.

Exam Tips

  • Memorise symbols of first 20 elements
  • Practice calculating protons, neutrons, electrons from Z and A
  • Practice drawing Bohr diagrams
  • Valency: if outermost ≤ 4, valency = outermost; if > 4, valency = 8 - outermost

Bright Tutorials | ICSE Class VII Chemistry | Chapter 3: Atomic Structure | Contact: 9403781999