Valence Electrons and Oxidation States

The video tutorial explains how to determine the number of valence electrons in an atom using the octet rule. It provides examples with sodium, beryllium, and fluorine to illustrate how to calculate oxidation numbers. Sodium loses an electron, beryllium loses two, and fluorine gains one to achieve stable electron configurations. The tutorial emphasizes the relationship between valence electrons and oxidation numbers across different elements.

What is the primary rule used to determine the number of valence electrons in an atom?

• Octet Rule

• Bohr's Rule

• Periodic Rule

• Electron Rule

How many valence electrons does a sodium atom have?

• One

• Two

• Three

• Four

What happens to sodium's outermost energy level when it loses one electron?

• It gains an electron

• It becomes incomplete

• It disappears

• It remains unchanged

What is the oxidation number of sodium after it loses one electron?

• +2

• -1

• +1

• 0

How many valence electrons does beryllium have?

• Four

• Three

• Two

• One

What is the oxidation number of beryllium after it loses its valence electrons?

• -1

• +1

• +2

• 0

How many electrons does fluorine need to gain to achieve a full outer shell?

• One

• Two

• Four

• Three

What is the oxidation number of fluorine after it gains an electron?

• +2

• +1

• -1

• 0

Which of the following elements is likely to gain electrons to achieve stability?

• Beryllium

• Sodium

• Helium

• Fluorine

What do elements in the same group of the periodic table share?

• Same number of protons

• Same number of valence electrons

• Same number of neutrons

• Same atomic mass