Atomic Structure and Electron Configuration

The video tutorial explains the structure of an atom, focusing on the nucleus and electron arrangement. It covers how electrons are organized in shells around the nucleus, with specific examples of lithium, carbon, and magnesium. The tutorial also introduces dot and cross diagrams for representing electronic configurations and discusses how electron arrangements influence element reactivity and periodic table groupings.

What is the central part of an atom called?

• Electron

• Neutron

• Nucleus

• Proton

In a neutral atom, the number of electrons is equal to the number of what?

• Protons

• Neutrons

• Nuclei

• Shells

How many electrons can the first shell of an atom hold?

• Eight

• Four

• Two

• Six

What is the maximum number of electrons that can be held in shells after the first one?

• Eight

• Six

• Four

• Two

How is the electronic configuration of lithium written?

• Li 2 1

• Li 2 2

• Li 1 2

• Li 3 0

In a dot and cross diagram, what does the central black dot represent?

• Nucleus

• Proton

• Electron

• Shell

What is the electronic configuration of carbon?

• C 2 4

• C 2 2

• C 4 2

• C 6 0

How many electrons does magnesium have in its third shell?

• Two

• Eight

• Four

• Six

What determines the group number of an element on the periodic table?

• Number of electrons in the outer shell

• Number of energy levels

• Number of protons

• Number of neutrons

Elements in the same group of the periodic table have similar what?

• Colors

• Reactivities

• Sizes

• Masses