periodicity: Atomic radius and Ionization

As you move down the periodic table atoms get bigger.  This is because ____________.

• The atoms have more mass.
• The atoms have more protons.
• The atoms have more energy levels
• The atoms have more nuetrons

List the following in order of weakest to strongest ionization energy.
P, Cs, Co, Sr

• P, Co, Sr, Cs
• Cs, Sr, Co, P
• Sr, Cs, Co, P
• P, Co, Cs, Sr

Which of the following elements has the smallest atomic radius?

• Sulfur

• Chlorine

• Aluminum

• Sodium

Which atom has the largest atomic radius?

• potassium

• rubidium

• francium

• cesium

Which of the following will have a lower ionization energy than Scandium (Sc)?

• Helium (He)

• Titanium (Ti)

• Calcium (Ca)

• Magnesium (Mg)

Atomic radius generally increases as we move __________.  

• down a group and from right to left across a period 
• up a group and from left to right across a period 
• down a group and from left to right across a period 
• up a group and from right to left across a period 

Ionization energy is...

• the energy required to add an electron to a specific atom
• how much energy it takes to remove an electron from an atom
• the energy required to shield the outer electrons from the nucleus
• a measure of the ability of an atom to attract electrons

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.

As you move across a period the # of valence electrons...

• will change and increase

• will change and decrease

• stay the same or no change

As you down a group, the number of valence electrons will...

• change and increase

• change and decrease

• stay the same