Periodic Trends

Question 1

What is a periodic trend?

Answer 1

They are specific patterns in the properties of chemical elements that are shown in the periodic table

Question 2

Atomic Radius

Answer 2

• Measurement of the size of an atom
• It is determined by measuring the distance between bonded nuclei
• ↓←

Question 3

Ionic Radius

Answer 3

• Measurement of the size of an ion
• Cations (+) are always smaller than the neutral atom
  
  • The more electrons removed the smaller the ionic radius
• Anions (-) are always larger than the neutral atom
  
  • The more electrons added the larger the ionic radius
• ↓←

Question 4

Ionization Energy

Answer 4

• Amount of energy required to remove an electron
• The alkali metals have the lowest ionization energies while noble gases have the highest
• →↑

Question 5

Electron Affinity

Answer 5

• Energy change that occurs when an electron is added to an atom in the gaseous state
• →↑

Question 6

What groups have low electron affinities?

Answer 6

• Atoms in groups 1 and 2
• They don’t attract electrons

Question 7

What groups have high electron affinities?

Answer 7

• Atoms in groups 16 and 17
• They attract electrons strongly

Question 8

What is a group?

Answer 8

• A column of elements down the periodic table
• vertical

Question 9

What is a period?

Answer 9

• A horizontal row across the periodic table