Periodic Table Section 1 Quiz

Match it! Select the correct answer from the pull down...Good luck!

The model we use today is the .....

Protons + Neutrons =

The smallest form of matter that still has the properties of a specific element.

An isotope of an element has the same number of protons, but different numbers of _____________

Who discovered that electrons are found in different energy levels or shells?

Positively charged particles of an atom.

Number of protons

Who discovered the electron?