General

Question 1

Why does certain element have the ability to conduct electricity?

Answer 1

• Metallic nature of atom
• Has low ionization energy
• Allow free delocalized electron jump from bond to bond

Question 2

Describe the properties of a semi-metal

Answer 2

• Brittle
• Can conduct electricity better than insulator but worst than conductors
• Solid
• Conductivity depends on impurities/holes electron can flow through

Question 3

What is the same in a period? The Physical or chemical property?

Answer 3

Physical

Question 4

What is the same in a group? The Physical or chemical property?

Answer 4

Chemical (P block depends on state)

Question 5

Moving to the right of the periodic table, describe the properties of the atom

Answer 5

• Atomic radii decrease
• Ionization energy increase
• Electronegativity increase
• Effective nuclear charge increase
• Shielding effect consant

Question 6

Moving to the bottom of the periodic table, describe the properties of the atom

Answer 6

• Atomic radii increase
• Ionization energy decrease
• Electronegativity decrease
• Effective nuclear charge increase
• Shielding effect increase

Question 7

Definition of oxidation state

Answer 7

The oxidation state is the hypothetical charge an atom would have if all bonds to it were fully ionic, indicating the degree of electron loss or gain.

Question 8

Describe the differences between the oxidation states of metal, non-metal and transition metals

Answer 8

• Most metals have +ve ion
• Most non-metals have -ve ion
• Most transition metals have both

Question 9

Who can oxygen bond with?

Answer 9

Almost all except for noble gasses

Question 10

Why can most oxide form at least one oxide that is stable

Answer 10

• Because the negative free energy of formation
• Formation of oxide is favorable

Question 11

Explain Ionic hydride

Answer 11

Melting- Hydride (H-) That forms with alkaline earth metal
- High Melting point
- Form white crystalline solid
- High reactivity

Question 12

Explain Covalent hydride

Answer 12

• Hydride that forms with G13-G17
• Elements with small but high charge density element are more covalent nature
• But heavier elements produce involatile hydride and acts as an intermediate between ionic and covalent hydride

Question 13

Define effective nuclear charge

Answer 13

The effective nuclear charge is the net positive charge experienced by an electron in an atom, accounting for both the actual nuclear charge and the shielding effect of inner electrons.

Question 14

Define shielding effect

Answer 14

The shielding effect is the reduction in attraction between the nucleus and outer electrons due to the repulsion from inner-shell electrons.