Valency is the combining capacity of an element. It is also defined as the number of hydrogen atoms or chlorine atoms or twice the number of oxygen atoms that combine with one atom of an element to form a compound.

The number of valence electrons of an element that is involved in chemical reactions is called the valency of that element. Valency of an element is the measure of combining capacity with other atoms when it forms a chemical compound or molecule.

The electronic configurations of three elements X , Y and Z are: X ⇒ 2 , Y ⇒ 2 , 8 , 7 Z ⇒ 2 , 8 , 2 Which of the following is correct regarding these elements?

Y is a non-metal and Z is a metal

EASY

Earn 100

Explain why ionic compounds are brittle.

Important Questions on Model

MEDIUM

Chemistry>Systems>Model>Ionic Compounds and their Properties

Give two general properties of ionic compounds and two those of covalent compounds.

MEDIUM

Chemistry>Systems>Model>Ionic Compounds and their Properties

Give the names and formulae of two pentatomic and two tetratomic anions.

EASY

Chemistry>Systems>Model>Ionic Compounds and their Properties

What is valency?

HARD

Chemistry>Systems>Model>Ionic Compounds and their Properties

The number of protons in one atom of an element

X

8

. What will be the number of electrons in its ion

X^{2 -}

MEDIUM

Chemistry>Systems>Model>Ionic Compounds and their Properties

Mendeleev predicted the existence of certain elements not known at that time and named two of them as eka-silicon and eka-aluminium.
(a) Name the elements which have taken the place of these elements.
(b) Mention the group and the period of these elements in the modern periodic table.
(c) How many valence electrons are present in each one of them?

MEDIUM

Chemistry>Systems>Model>Ionic Compounds and their Properties

Define ion, cation and anion.

MEDIUM

Chemistry>Systems>Model>Ionic Compounds and their Properties

Give one example each of
a. cation
b. anion
c. polyatomic ion.

EASY

Chemistry>Systems>Model>Ionic Compounds and their Properties

Define valency.

EASY

Chemistry>Systems>Model>Ionic Compounds and their Properties

A group of atoms carrying a fixed charge on them is called _____ ions. (triatomic/ polyatomic)

EASY

Chemistry>Systems>Model>Ionic Compounds and their Properties

The valency of an element with atomic number 2 is_____.

MEDIUM

Chemistry>Systems>Model>Ionic Compounds and their Properties

The electronic configurations of three elements $X, Y$ and $Z$ are:

$X \Rightarrow 2, Y \Rightarrow 2, 8, 7 Z \Rightarrow 2, 8, 2$

Which of the following is correct regarding these elements?

MEDIUM

Chemistry>Systems>Model>Ionic Compounds and their Properties

Write electron-dot structures for magnesium and oxygen.

EASY

Chemistry>Systems>Model>Ionic Compounds and their Properties

What are polyatomic ions? Give examples.

MEDIUM

Chemistry>Systems>Model>Ionic Compounds and their Properties

The electronic configurations of three elements

X, Y

and

Z

are as follows:

X

2

4

Y

2

7

Z

2

1

(a) Which two elements will combine to form an ionic compound?
(b) Which two elements will react to form a covalent compound?
Give reasons for your choice.

HARD

Chemistry>Systems>Model>Ionic Compounds and their Properties

State the properties of ionic compounds.

EASY

Chemistry>Systems>Model>Ionic Compounds and their Properties

Identify the cation and anion present in the compound potassium dichromate.

EASY

Chemistry>Systems>Model>Ionic Compounds and their Properties