Understanding Valency in Chemistry

This video tutorial explains the concept of valency, which is the number of electrons an element can accept or donate to form chemical bonds. It covers examples of elements like hydrogen, helium, magnesium, fluorine, oxygen, and sulfur, discussing their valency and how it affects their bonding behavior. The video also highlights the difference between metals and nonmetals in terms of electron donation and acceptance. Special attention is given to sulfur's unique ability to have different valencies depending on its bonding partners. The tutorial concludes with additional resources for further learning.

What does valency describe in an element?

• The number of electrons an element can accept or donate

• The atomic mass of the element

• The number of neutrons in the nucleus

• The number of protons in the nucleus

What is the valency of hydrogen?

• 1

• 3

• 0

• 2

Why is helium considered to have a valency of 0?

• It has no electrons

• It is a noble gas and does not form bonds

• It can donate electrons easily

• It has a high atomic number

What happens to magnesium when it loses its valence electrons?

• It becomes a noble gas

• It forms a cation with a 2+ charge

• It becomes a neutral atom

• It forms an anion with a 2- charge

How many valence electrons does fluorine have?

• 5

• 6

• 7

• 8

What is the valency of oxygen and why?

• 1, because it needs one more electron

• 2, because it needs two more electrons to complete its octet

• 3, because it can form three bonds

• 4, because it has four valence electrons

In water, how many bonds does oxygen typically form?

• One

• Four

• Two

• Three

What can sulfur do to achieve stability?

• Neither gain nor lose electrons

• Only lose electrons

• Either gain or lose electrons depending on the situation

• Only gain electrons

When sulfur is bonded to hydrogen, what is its valency?

• 2

• 1

• 4

• 6

In sulfuric acid, how many bonds does sulfur form?

• Eight

• Two

• Four

• Six