Determining Valence Electrons from the Periodic Table

Dr. Williams explains valence electrons, their role in chemical properties, and how to determine them using the periodic table. The video covers valence electrons in groups 1 and 2, and groups 13 to 18, with examples and practice exercises. It highlights the relationship between group numbers and valence electrons, emphasizing the differences in transition metals.

What are valence electrons?

• Electrons in the innermost shell

• Electrons in the outermost shell

• Protons in the nucleus

• Neutrons in the nucleus

How many valence electrons does lithium have?

• 4

• 1

• 2

• 3

Which group does magnesium belong to?

• Group 18

• Group 3

• Group 2

• Group 1

Why can't the method of determining valence electrons be used for transition metals?

• They have variable valence electrons

• They are gases at room temperature

• They do not have valence electrons

• They only have one valence electron

What is the number of valence electrons in chlorine?

• 8

• 7

• 5

• 3

How do you determine the number of valence electrons for elements in groups 13 through 18?

• Add 10 to the group number

• Use the group number directly

• Subtract 10 from the group number

• Multiply the group number by 2

How many valence electrons does carbon have?

• 2

• 4

• 8

• 6

Which element has one valence electron?

• Calcium

• Helium

• Neon

• Hydrogen

How many energy levels does helium have?

• 1

• 2

• 4

• 3

What is the maximum number of valence electrons helium can have?

• 8

• 4

• 2

• 1