Periodic Table Trends

Question 1

Why do halogens tend to form anions?

Answer 1

Gaining electrons will fill their octet faster than losing them.

Question 2

Describe the periodic trends for atomic radius

Answer 2

• Atomic radius decreases from left to right across the periodic table.
• Atomic radius increases down the periodic table.

Question 3

Describe the periodic trends for ionization energy

Answer 3

• First ionization energies increase from left to right across the periodic table.
• First ionization energies decrease down the periodic table.

Question 4

First ionization energies ___ from left to right across the periodic table

Answer 4

Increase

Question 5

First ionization energies ___ down the periodic table

Answer 5

Decrease

Question 6

Describe the electronegativity of the atoms in a polar covalent bond

Answer 6

One atom in the bond must have higher electronegativity than the other atom

Question 7

Define ionization energy

Answer 7

The amount of energy required to remove a valence electron from an atom

Question 8

A graph of the ionization energies of the elements in the first three periods is shown below.

Which atoms are least likely to lose an electron?

Answer 8

Group 8A: noble gases

Noble gases have high ionization energies, which means it is more difficult to remove an electron.

Question 9

Which group in the periodic table has the atoms that are most likely to lose an electron?

Answer 9

Group 1A: alkali metals

Alkali metals have low ionization energies, which means it is easier to remove an electron.

Question 10

Why do alkali metals have lowest ionization energy?

Answer 10

After the loss of an electron, the alkali metals have a stable noble gas configuration

Question 11

Which group has the atoms that are most likely to lose two electrons?

Answer 11

Group 2A: alkaline earth metals

After the loss of two electrons, the alkaline earth metals have a stable noble gas configuration.

Question 12

A more electronegative atom will have ___ attraction to the electrons in a chemical bond

Answer 12

More

Question 13

Atomic radii decrease from left to right in a period (Na → Ar) on the periodic table.

Explain this trend

Answer 13

The nuclear charge increases in that direction

Question 14

Elements that are most similar in their properties are found in the same _____

Answer 14

Group

Question 15

_________ is a measure of an atom’s ability to attract electrons.

Answer 15

Electronegativity

Question 16

Electronegativity ________ from left to right across a period on the periodic table and _______ from top to bottom of a group on the periodic table.

Answer 16

Increases, decreases
(follows the same trend as ionization energy)

Question 17

Describe the periodic trends for atomic radius.

Answer 17

• Atomic radius decreases from left to right across the periodic table.
• Atomic radius increases down the periodic table.

Question 18

Explain why alkali metals have the lowest ionization energy

Answer 18

After the loss of an electron, the alkali metals have a stable noble gas configuration

Question 19

Atomic radii decrease from left to right in a period (Na → Ar) on the periodic table. Explain this trend

Answer 19

• The nuclear charge increases in that direction.
• As the nuclear charge increases, all electrons in the outer shell (in this case the third shell) are attracted more strongly to the nucleus and are pulled closer to the nucleus.