Periodic Trends

How many valence electrons does this group have?

• 1

• 2

• 7

• 8

Which element has an atomic radius that is LARGER than sodium?

• Lithium (Li)

• Hydrogen (H)

• Magnesium (Mg)

• Potassium (K)

When oxygen becomes an ion, does it get larger or smaller?

• larger

• smaller

• depends on which isotope of oxygen it is

• oxygen forms several ions so it's impossible to tell

Based on the trends we learned, which has the lowest ionization energy?

• phosphorus (P)

• sulfur (S)

• arsenic (As)

• selenium (Se)

Which element has two electron shells?

• Helium (He)

• Neon (Ne)

• Argon (Ar)

• Krypton (Kr)

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 alkali metal is the least reactive?

• Li

• Na

• H

• Fr

Ionization energy is the...

• energy needed to remove the outermost electron.
• ability of an atom to attract electrons from another atom.

The electrons in the outer most energy level of an atom is also known as

• Active electrons

• Inert electrons

• Valence electrons

• None of the above