3.7 Periodic Trends Review

What's a valence electron?

• electrons in the second energy level
• electrons in the outermost energy level
• the atomic number
• electrons in the first level

Which element in Period 2 has the greatest atomic radius?

• Be

• C

• Na

• Li

Of the halogens, which has the smallest radius?

• F

• Br

• He

• At

Which of the alkaline-earth metals has the smallest electronegativity

• Be

• Sc

• Ra

• Sr

As you move down a group, atomic radius increases because - 

• you add more and more neutrons
• you add more and more protons
• you add more and more shells (energy levels)
• you add more atomic mass

As you move across the periodic table from left to right, the atomic radius decreases.  This is because - 

• the number of protons increases, so attraction to electrons increases
• the number of energy levels increases
• the number of electrons increases
• the atomic mass increases

Francium (Fr) has the lowest ionization energy in Group 1 because - 

• it has the smallest number of valence electrons
• it has the greatest atomic mass
• it has the greatest number of protons, so it attracts its electrons the strongest
• its 1 valence electron is very far from the nucleus, so little energy is needed to remove it

The element with the smallest ionization energy in Period 6 is - 

• Rn
• Cs
• Os
• Tm

As you move across the periodic table atoms tend to get smaller because, ______________.

• the atoms have more mass.
• the atoms have less mass
• the atoms have more protons.
• the atoms have less electrons.

The energy required to remove electrons is the definition of: 

• Electronegativity
• Atomic Number
• Atomic Radius
• Ionization