January 17-18 Opener

The atomic number indicates the number of ​ (a)   in an atom.

• protons
• electrons
• neutrons
• protons + neutrons

Groups are ​ (a)   on the periodic table.

• columns
• rows

Periods are ​ (a)   on the periodic table

• rows
• columns

Groups tell us the number of ​ (a)   on a neutral atom of that element

• valence electrons
• energy levels

Periods tell us the number of ​ (a)   on a neutral atom of the element.

• energy levels
• valence electrons

As you look down a group, the atomic radius ​ (a)  

• increases
• decreases

As you look down a group, each new row's atoms ​ (a)  

• add more energy levels
• add more valence electrons

As you look across a period, the atomic radius of the elements ​ (a)  

• decreases
• increases

As you look across a period, ​ (a)  

• the nucleus attracts the valence electrons more
• more energy levels are added

Electronegativity is the tendency to ​ (a)   ​ electrons on the valence shell.

• gain
• lose