9
Question Question 9
Differentiate between the following with suitable examples — A basic radical and a acid radical.
| Basic radical | Acid radical |
|---|---|
| It is a radical which behaves like hydrogen or a metal in a chemical reaction. | It is a radical which behaves like a non-metal in a chemical reaction. |
| The positive part of a compound is called the basic radical. | The negative part of a compound is called the acid radical. |
| Example: In Sodium nitrate, Na+ is the basic radical. | Example: In Sodium nitrate, NO3- is the acid radical. |
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