pericodity atomic and ionic electronegativity

Question 1

atomic radii

Answer 1

Describes the size of an atom

Question 2

what effects radius

Answer 2

electron shells
nuclear attraction
electron sheilding

Question 3

how does electron shells effects the radius

Answer 3

The more shells the larger the atom becomes
leads to larger atomic radius

Question 4

how does nuclear attraction effects the radius

Answer 4

The more protons in the nucleus, the more attraction is felt by the outer shell electron.

Leads to smaller atomic radius

Question 5

how does electron shielding effect the radius

Answer 5

Inner shell electrons repel the outer shell electrons so they don’t feel much attraction from the nucleus.

More shielding leads to a larger atomic radius

Question 6

which elements has a smaller atomic radius and explain why
Lithium and potassium

Answer 6

Lithium has a smaller atomic radius than potassium
Lithium and potassium are in the same group .
Lithium has 2 less shell than potassium

Question 7

which elements has a smaller atomic radius and explain why
Sulphur or Aluminium

Answer 7

Sulfur is smaller than aluminium.

Sulfur and aluminum are in the same period so they have the same number of shells so shielding is constant.

Sulfur has more protons so there is a greater nuclear attraction

Question 8

Effective nuclear charge
What happens when you lose electron

Answer 8

Lose electrons = get smaller. Same number of protons but less electrons to attract. Effective nuclear charge is increased

Question 9

Effective nuclear charge
What happens when you gain electrons

Answer 9

get bigger. Same amount of shielding and protons but more electrons to attract. Effective nuclear charge is reduced.

Question 10

Which has a smaller radius and explain why
Na or Na+

Answer 10

Na+ because it has lost an electron but same number of protons. Effective nuclear charge is increased. Has 1 less shell.

Question 11

which has a smaller radius and explain why
Na+ or Mg2+

Answer 11

Mg2+ because it has lost 2 electrons rather than 1 so effective nuclear charge is greater.

Question 12

electronegativity

Answer 12

measure of tendency of an atom to attract a pair of electrons in a covalent bond

Question 13

which elements is more electronegative
Cl or Br

Answer 13

Cl = less electron shells, less electron shielding, higher nuclear attraction

Question 14

which elements is more electronegative
Si or Na

Answer 14

Si = higher nuclear attraction, same shielding and shells (same period)

Question 15

What is the trend in atomic radii down a group and across a period

Answer 15

Down a group - increases
Across a period - decreases

Question 16

Explain the trends of a group and period

Answer 16

Down a group - increases because more shells = more electron shielding = less nuclear attraction
Across a period - decreases because same shells and electron sheilding
but more nuclear attraction (more protons in nucleus)

Question 17

What happens to the size of atoms when they become ions

Answer 17

Gain electrons = size increases

Lose electrons = size decreases

Question 18

Why is helium more electronegative than hydrogen?

Answer 18

Same period = same number of shells = same shielding but helium has greater nuclear attraction as more protons in the nucleus