Valency and Chemical Properties of Elements

This video tutorial from Win Point Online Classes covers the periodic classification of elements, focusing on the concept of valency. It explains valency as the combining capacity of an element, using examples like phosphorus and sodium to illustrate how valency is determined by the number of electrons in the outermost shell. The tutorial also discusses how valency varies across groups and periods in the periodic table, with specific attention to elements in the second period. The session aims to provide a comprehensive understanding of valency and its significance in chemical reactions.

What is valency?

• The atomic mass of an element

• The number of protons in an atom

• The combining capacity of an element

• The number of neutrons in an atom

What is the atomic number of phosphorus?

• 17

• 16

• 14

• 15

How many electrons are in the valence shell of sodium?

• 1

• 4

• 3

• 2

Why do atoms participate in chemical reactions?

• To gain protons

• To lose neutrons

• To complete the octet in the outermost shell

• To change their atomic number

What happens to the valency down a group?

• It fluctuates

• It decreases

• It increases

• It remains the same

What is the valency of hydrogen?

• 3

• 0

• 1

• 2

Which group does lithium belong to?

• Group 13

• Group 2

• Group 1

• Group 14

What is the valency of carbon?

• 2

• 3

• 4

• 5

How many electrons are in the outermost shell of oxygen?

• 4

• 5

• 6

• 7

What is the valency of neon?

• 3

• 2

• 0

• 1