Science Lessons

Category 1 Review (8.5B)

Protons & Valence electrons

A = P = E

Atomic # = # protons = # electrons

*Positive charge

*Mass equivalent to 1 AMU (atomic mass unit)

Multiple Choice

Why are protons so important?

• because they are in the nucleus

• because they are positive

• because they determine the identity of the element

Multiple Choice

Up to how many electrons can the 1st, 2nd and 3rd shell hold?

• 2:8:8

• 8:8:2

• 8:2:8

Multiple Choice

What is a valence electron?

• is a regular electron

• is an electron found on the outermost shell that bonds with other atoms

• is a super subatomic particle

• is a dense subatomic particle that helps determine the atoms charge

Multiple Select

What do valence electrons help us determine?

• mass of an element

• chemical properties

• reactivity

• charge