Periodic Trends

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 atom with the largest atomic radius in Group 18 is - 

• Ar
• He
• Kr
• Rn

Which statement correctly and completely identifies a trend?

• Atomic radius decreases across a period and increases down a group.

• Electronegativity decreases across a period and decreases down a group.

• Ionization energy increases across a period and increases down a group.

• Ionic radius increases across a period and increases down a group.

Electronegativity is...

• how good an atom is at attracting electrons
• the ability of an atom to lose electrons
• the energy required to remove an electron from a specific atom
• how easy it is to make friends. 

As you look down a group, electronegativity

• increases

• decreases

As you look from left to right across a period, electronegativity

• increases

• decreases

What is ionization energy?

• Energy needed to destroy an atom
• Energy required to remove an electron
• Energy needed to split an electron
• Energy required to add an electron

Which element has the greater ionization energy?

• Magnesium (Mg)

• Phosphorus (P)

Which element has the greater ionization energy?

• Iodine (I)

• Chlorine (Cl)

Which has the greater EN: 
N or C?

• C
• N