Valency and Stability of Elements

The video tutorial explains the concept of valency in chemistry, using examples of hydrogen, oxygen, sodium, and magnesium to illustrate how atoms achieve stability. It discusses the variable valency of transition metals like zinc, copper, and iron. The tutorial also provides a method to determine valency based on periodic table groups, distinguishing between metals and non-metals. Finally, it clarifies the difference between valency and oxidation state, emphasizing that they are distinct concepts.

What is the valency of hydrogen, and why?

• 1, because it needs one more electron to complete its duplet.

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

• 1, because it needs one more electron to complete its octet.

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

How does oxygen achieve stability?

• By gaining one electron.

• By losing two electrons.

• By gaining two electrons.

• By losing one electron.

What is the valency of sodium, and how does it achieve stability?

• 1, by losing one electron.

• 2, by gaining two electrons.

• 2, by losing two electrons.

• 1, by gaining one electron.

How does magnesium achieve stability?

• By losing one electron.

• By gaining two electrons.

• By gaining one electron.

• By losing two electrons.

Which of the following transition metals can have a valency of either two or three?

• Hydrogen, Oxygen, and Nitrogen

• Zinc, Copper, and Iron

• Sodium, Magnesium, and Calcium

• Carbon, Silicon, and Phosphorus

How is the valency of group one metals determined?

• It is always zero.

• It is equal to the group number.

• By adding the group number to 8.

• By subtracting the group number from 8.

What is the valency of group seven non-metals?

• 1, because 8 - 7 equals 1.

• 2, because 8 - 6 equals 2.

• 3, because 8 - 5 equals 3.

• 0, because 8 - 8 equals 0.

How do you calculate the valency of group four non-metals?

• By subtracting 4 from 8.

• By adding 4 to 8.

• By multiplying 4 by 2.

• By dividing 8 by 4.

What is the difference between valency and oxidation state?

• Valency is the same as oxidation state.

• Valency is the combining capacity, while oxidation state can vary in different compounds.

• Valency is always positive, while oxidation state is always negative.

• Valency is always zero, while oxidation state is not.

What is the valency of carbon, and how does it differ from its oxidation state?

• Valency is zero, while oxidation state can be +4 or +2.

• Valency is four, while oxidation state can be +4 or +2.

• Valency is two, while oxidation state can be +4 or +2.

• Valency is four, while oxidation state is always +4.