PT Self Check 3

In the periodic table, elements are listed in rows according to their ___________.

• date of discovery

• atomic radius

• atomic number

• atomic mass

Phosphorus (P) has ____ protons in its nucleus.

• 15

• 20

• 17

• 12

A neutral atom of oxygen has ___ electrons.

• 2

• 4

• 6

• 8

How many neutrons does Beryllium (Be) have?

• 4

• 5

• 9

• 20

Periods tell this about an element.

• Number of electron orbitals.

• Number of valence electrons.

• Number of protons

• Number of neutrons

Groups tell this about an element.

• Number of electron orbitals.

• Number of valence electrons.

• Number of protons

• Number of neutrons

Period 3, group 13 element.

• Aluminum

• Boron

• Gallium

• Silicon

Dot diagrams, like the image, show the _______ of an element.

• valence electrons

• electron orbitals

• protons

• neutrons

Valence electrons are located in the ___________ orbital.

• outermost

• innermost

• middle

• first

The outermost electron orbital can generally hold ___ electrons.

• 2

• 4

• 6

• 8