What do you mean by the valency of an element?

Important Questions on The Language of Chemistry

EASY

7th CBSE

IMPORTANT

Basic Science For Class 7>Chapter 1 - The Language of Chemistry>Exercises>Q A

What is a group of atoms of two or more elements behaving like an atom and having a valency is called?

MEDIUM

7th CBSE

IMPORTANT

Basic Science For Class 7>Chapter 1 - The Language of Chemistry>Exercises>Q A

Name two elements that have variable valency. Give the formula and name of two compounds formed by each of these elements.

MEDIUM

7th CBSE

IMPORTANT

Basic Science For Class 7>Chapter 1 - The Language of Chemistry>Exercises>Q A

What is balanced chemical equation? Why should a chemical equation be balanced?

MEDIUM

7th CBSE

IMPORTANT

Basic Science For Class 7>Chapter 1 - The Language of Chemistry>Exercises>Q B

Find the valences of the underlined elements or radicals in the following compounds.
$\underset{\_}{\mathrm{B}\mathrm{a}}\mathrm{C}{\mathrm{l}}_2,\underset{\_}{ \mathrm{P}}\mathrm{C}{\mathrm{l}}_3, \underset{\_}{\mathrm{P}}\mathrm{C}{\mathrm{l}}_5, \underset{\_}{\mathrm{N}}{\mathrm{H}}_3, \mathrm{M}\mathrm{g}\underset{\_}{\mathrm{S}{\mathrm{O}}_4}, \mathrm{C}\mathrm{a}\underset{\_}{\mathrm{C}{\mathrm{O}}_3}, \underset{\_}{\mathrm{N}{\mathrm{a}}_2}\mathrm{O}, \underset{\_}{\mathrm{C}\mathrm{a}}\mathrm{O},\underset{\_}{ \mathrm{C}\mathrm{a}}{\left(\mathrm{O}\mathrm{H}\right)}_2,\underset{\_}{ \mathrm{F}\mathrm{e}}\mathrm{S}{\mathrm{O}}_4,$
$\underset{\_}{\mathrm{F}\mathrm{e}}\mathrm{C}{\mathrm{l}}_3,\underset{\_}{ \mathrm{F}{\mathrm{e}}_2}{\mathrm{O}}_3, \mathrm{N}\mathrm{a}\underset{\_}{\mathrm{O}\mathrm{H}}, \underset{\_}{\mathrm{A}\mathrm{l}}{\left(\mathrm{O}\mathrm{H}\right)}_3,\underset{\_}{ \mathrm{N}{\mathrm{a}}_2}\mathrm{C}{\mathrm{o}}_3$

HARD

7th CBSE

IMPORTANT

Basic Science For Class 7>Chapter 1 - The Language of Chemistry>Exercises>Q C

What are compound radicals? Give examples of a few radicals, along with their valences. Also mention some compounds containing compound radicals. Give the valencies of the parts that make up the compound.

EASY

7th CBSE

IMPORTANT

Basic Science For Class 7>Chapter 1 - The Language of Chemistry>Exercises>Q D

A _____ is an abbreviation of the name of an element.

EASY

7th CBSE

IMPORTANT

Basic Science For Class 7>Chapter 1 - The Language of Chemistry>Exercises>Q D

A molecule of an element or a compound is represented by its _____. (Valency/ formula)

EASY

7th CBSE

IMPORTANT

Basic Science For Class 7>Chapter 1 - The Language of Chemistry>Exercises>Q D

The valencies of the two elements of a binary compound are _____ to obtain its formula. (added / transposed)