Periodicity

Question 1

What is the outer shell called?

Answer 1

Valence shell

Question 2

What is ionisation energy?

Answer 2

Energy required to release an electron and become an ion

Question 3

What is the octet rule?

Answer 3

Atoms desire to form a stable octet (noble gas)

Question 4

Why is the periodic table useful?

Answer 4

Properties and trends of elements are the basis of the periodic table’s design so allows accurate predictions of properties and reactions of a wide variety of substances

Question 5

What are the chemical properties of metals?

Answer 5

Tend to lose e- and form positive ions

Question 6

What are the physical properties of metals?

Answer 6

• Lustrous
• Malleable
• Good conductors of heat
• Good conductors of electricity

Question 7

What are the chemical properties of nonmetals?

Answer 7

Tend to gain e- and form negative ions

Question 8

What are the physical properties of nonmetals?

Answer 8

• Non-lustrous
• Brittle
• Poor conductors of heat
• Poor conductors of electricity

Question 9

What properties do metalloids have?

Answer 9

Properties that are intermediate between metals and nonmetals

Question 10

What happens when metals react with nonmetals?

Answer 10

E- are usually transferred from the metal to the nonmetal

Question 11

Where are metals found on the periodic table?

Answer 11

The left of the metalloids

Question 12

Where are nonmetals found on the periodic table?

Answer 12

The right of the metalloids

Question 13

What is the screening factor?

Answer 13

The number of inner core electrons

Question 14

How do you calculate the effective nuclear charge?

Answer 14

Number of protons - screening factor

Question 15

what does Zeff stand for?

Answer 15

Effective nuclear charge

Question 16

What is the trend of effective nuclear charge on the periodic table?

Answer 16

Increases across the periodic table

Question 17

Why does effective nuclear charge increase as you move across to the right of the periodic table?

Answer 17

Additional valence electrons counterbalance the nuclear charge

Question 18

What is the trend of atomic volume on the periodic table?

Answer 18

• Radii of atoms increases down a group
• Quantum (electron) number increases and are further away from nucleus
• Radii decreases from left to right
• Zeff is increased each time an electron is added, as a proton is added to the nucleus as well

Question 19

What are the trends in ionisation energy?

Answer 19

• Smaller atoms have higher ionisation energies
• Decreasing the distance of the electron from the nucleus or increasing Zeff, increases IE
• The lower the IE, the easier to lose an electron to become a positive ion

Question 20

Which one has lower ionisation energies: metals or nonmetals?

Answer 20

Metals

Question 21

What is electron affinity?

Answer 21

Energy liberated when an element (in gas phase) gains an electron, becoming a negative ion

Question 22

Which one has higher electron affinities: metals or nonmetals?

Answer 22

Nonmetals

Question 23

Why are ionisation energy and electron affinity important?

Answer 23

Elements with low ionisation potential can easily give their electrons to elements with high electron affinities, forming an ionic bond and a complete valence shell