Chapter 5 - Electrons and Bonding

Question 1

What are shells?

Answer 1

➜ energy levels
➜ energy increases as shell n.o increases
➜ shell number is called the principal quantum number n

Question 2

Atomic Orbitals

Answer 2

➜ region around nucleus that holds up to 2 e⁻ with opposite spins
➜ can hold 1 or 2 e⁻ and no more
➜ s, p, d, f
➜ each orbital has a diff shape

Question 3

S Orbitals

Answer 3

➜ shape of a sphere
➜ group 1 and 2
➜ each shell from n =1 contains 1 s orbital
➜ greater the shell number n the greater radius of s-orbital

Question 4

P Orbitals

Answer 4

➜ shape of a dumb-bell
➜ group 13 to 18 excluding Helium
➜ 3 separate p-orbitals at right angles to one another (Pₓ, Pᵧ, Pz)
➜ Each shell from n = 2 contains 3 p orbitals
➜ greater the shell number n, the further the p orbital is from the nucleus

Question 5

d orbitals and f orbitals

Answer 5

➜ each shell from n = 3 contains 5 d orbitals
↳ transition metals
➜ each shell from n = 4 contains 7 f orbitals
↳ extra box at bottom

Question 6

Electron config of Chromium

Answer 6

1s² 2s² 2p6 3s² 3p⁶ 3d⁵ 4s¹

Question 7

Electron config of Copper

Answer 7

1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s¹

Question 8

The 4s sub shell fills before the 3d sub shell!

Answer 8

also empties before 3d

Question 9

Ionic bonding

Answer 9

➜ electrostatic attraction between positive and negative ions
➜ Cations - positive ions (CATTSS)
➜ Anions - negative ions (ONIONS)

Question 10

Giant ionic lattice

Answer 10

➜ A 3D structure of oppositely charged ions bonded together by strong ionic bonds

Question 11

Melting and boiling points

Answer 11

➜ ionic compounds = solid at room temp due to insufficient energy to overcome strong electrostatic forces of attraction in giant ionic lattice
➜ therefore majority have high boiling/melting points

Question 12

Solubility

Answer 12

➜ ionic compounds dissolve in polar solvents
➜ water
➜ requires ionic lattice to break down
➜ requires water molecules to attract and surround ions

Question 13

Conductivity

Answer 13

➜ solid state
↳ ions are in fixed position
↳ no mobile charge carriers
➜ when dissolved or molten
↳ solid ionic lattice breaks down
↳ ions free to move as mobile charge carriers

Question 14

Covalent Bonding

Answer 14

➜ strong electrostatic attraction between a shared pair of electrons and nuclei of the bonded atoms
➜ non metals

Question 15

Orbital Overlap

Answer 15

➜ shared pair of e⁻ is attracted to the nuclei of both bonding atoms
➜ bonded atoms often have outer shells with the same electron structure as the nearest noble gas

Question 16

Localised

Answer 16

The attraction is solely between the shared pair of electron sin the covalent bond and nuclei of the bonding atom

Question 17

Multiple covalent bonds

Answer 17

exists when 2 atoms share more than one pair of e⁻

e. g double covalent bond = 2 shared pair of e⁻
e. g triple covalent bond = 3 shared pair of e⁻

Question 18

Dative covalent bonds (coordinate bonds)

Answer 18

➜ shared paid of e⁻ is supplied by one of the bonding atoms only
➜ the shared pair of e⁻ would have been originally a lone pair of electrons
e.g NH4₄⁻

Question 19

Less than 8 e⁻

Answer 19

➜ incomplete octet

Question 20

More than 8 e⁻

Answer 20

➜ expanded octet

➜ elements in period 3 due to d sub shell