Group and Valence Electron Properties

The video tutorial explains the modern periodic table, focusing on the trends in valence electrons and shells across different groups. It highlights how elements in the same group have similar valence electrons, leading to similar chemical properties. Specific groups like 1A, 2A, 7A, and 5A are discussed, showing how the number of valence electrons corresponds to the group number, affecting their valency and chemical behavior.

What is the total number of elements in the modern periodic table?

• 108

• 138

• 118

• 128

Which element in Group 1A has an electronic configuration of 2,8,8,1?

• Hydrogen

• Potassium

• Lithium

• Sodium

What is the common feature of Group 1A elements?

• Four valence electrons

• Three valence electrons

• Two valence electrons

• One valence electron

Which element in Group 2A has an electronic configuration of 2,2?

• Calcium

• Strontium

• Magnesium

• Beryllium

What is the trend in the number of shells for Group 2A elements?

• Varies randomly

• Remains constant

• Increases

• Decreases

How many valence electrons do Group 7A elements have?

• 5

• 8

• 6

• 7

What is the relationship between group number and valence electrons?

• Group number is half the valence electrons

• Group number equals valence electrons

• Group number is double the valence electrons

• No relationship

What is valency?

• Number of protons

• Number of neutrons

• Number of atoms in a molecule

• Number of electrons lost, shared, or gained

Why do elements in the same group have similar chemical properties?

• Same number of protons

• Same atomic number

• Same number of valence electrons

• Same number of neutrons

How many valence electrons do elements in Group 5A have?

• 5

• 4

• 6

• 3