Periodicity

Question 1

What is periodicity?

Answer 1

The study of repeating patterns or trends in physical and chemical properties across the periodic table

Question 2

What determines an element’s block in the periodic table?

Answer 2

The subshell in which its outer electrons are located

Question 3

What are the four blocks in the periodic table?

Answer 3

s - group 1 and 2
p - groups 3- 8
d - transition metals
f - lanthanides and actinides

Question 4

What is atomic radius?

Answer 4

The distance from the nucleus to the outermost electrons in an atom

Question 5

What happen to the atomic radius across period 3?

Answer 5

• increased nuclear charge (more protons)
• same shielding (electrons in the same energy level)
• stronger electrostatic attraction pulls electrons closer

Question 6

How do atomic radius change down a group?

Answer 6

• more electron shells
• greater shieling reduces attraction from the nucleus

Question 7

What is electronegativity?

Answer 7

The ability of an atom to attract pairs of electrons in a covalent bond

Question 8

How does electronegative change across period 3?

Answer 8

Increases from left to right

Question 9

Why does electronegativity increase across a period?

Answer 9

• More protons - stronger nuclear charge
• same shielding
• smaller atomic radius - electrons are closer to the nucleus

Question 10

Why are noble gases not included in the electronegativity series?

Answer 10

They don’t form covalent bonds readily so they don’t attract pairs of electrons