Exercise

Author:NCERT

NCERT Science Solutions for Exercise

Simple step-by-step solutions to Exercise questions of Gravitation from Science Textbook of Competency Based Questions for Class IX. Also get 3D topic explainers, cheat sheets, and unlimited doubts solving on EMBIBE.

Questions from Exercise with Hints & Solutions

MEDIUM
9th CBSE
IMPORTANT

The atomic mass of two elements are given below.

Oxygen = 16 u

Sulphur = 32 u

What is the ratio by atomic mass of Sulphur and Oxygen in SO2?

EASY
9th CBSE
IMPORTANT

Which of the following molecules is triatomic?

MEDIUM
9th CBSE
IMPORTANT

An ion of a metal is always positively charged.

MEDIUM
9th CBSE
IMPORTANT

An ion of a non-metal is either positively or negatively charged?

HARD
9th CBSE
IMPORTANT

The incorrect formula among the following is:

HARD
9th CBSE
IMPORTANT

The formula of a compound when a positive radical 'A’ with valency 2 and negative radical ‘B’ with valency 1 combine is _____.

HARD
9th CBSE
IMPORTANT

If the formula of a metal ion is M+2, then the formula of its dihydrogen phosphate is

HARD
9th CBSE
IMPORTANT

Arrange the following points in a sequence for derivation of formulae of compounds.

  1. The valencies of the ions or radicals are written below the radicals without positive and negative sign.
  2. If the valencies have common factors, then they are divided by the highest common factor.
  3. The magnitude of valencies should be interchanged and written as subscripts on the right side of the respective ions.
  4. The positive radical followed by negative radical are written with their charges.
  5. If the radicals have more than one atom, they are enclosed in brackets and the appropriate valency (more than one) is written as subscripts outside the bracket.