Trends

Question 1

Atomic Radii

Answer 1

Bigger to the left and down
Smaller to the right and up

Smaller explanation:
As you move right across a period all e- are adding to the same energy level and the #p+ is increasing. Thus ENC and attraction to the nucleus increases

Bigger Explanation:
As you move down a group the energy levels increase which in turn increases shielding greatly. The outer e- feels less ENC and are less attracted to the nucleus meaning they move farther away

Question 2

Ionic Radii

Answer 2

Increases to the left and down
Decreases to the left and up

Metals lose e- and Non-metals gain

Cations are always smaller
Anions are always bigger

Smaller Metal Explanation:
As you move to the right across a period the metals lose e- this removes the valence e- and exposes the lower energy e-. The shielding is much less on the new inner layer and the e- feel much greater ENC and are pulled closer to the nucleus

Bigger Non-metal explanation:
As you move across the period to the right non-metals gain electrons and the ENC doesn’t increase. The electrons push off each other pushing them away from the nucleus

Question 3

First Ionization Energy

Answer 3

The energy require to remove a valence electron

Atom must be in gas phase

Ex. Mg(g) + energy ➡️ Mg+(g) + e-

As you move to the right in a period the shielding stays constant and the ENC increases, as the attraction to the nucleus grows larger the amount of energy required to remove the e- also gets larger

*ENC is greatest on the right side of the table therefore on the right side is where ionization energy is the greatest

*shielding is greatest across the bottom of the table where ionization energy is lowest

More shieling = easier to remove

Question 4

Electron Affinity

Answer 4

Energy released when atoms gain e-

Increases to the top right
Decreases to the bottom left

ENC increases to the right, this means e- are more attracted to the nucleus and will release more energy when captured by an ion

*Affinity is always negative

*Higher affinity=more energy that comes out

Down on the PT affinity decreases because shielding is going up. The e- are less attracted and will release less energy if captured by an atom

Question 5

Electronegativity

Answer 5

The tendency an atom has to attract e- to itself

Electronegativity increase to the right because ENC increases and e- are more attracted to the nucleus and therefore drawn closer to the atom with greater ENC

Decreases down due to shielding going up. This results in e- being less attracted to atoms from the bottom of the table