Bonding 1-2

Question 1

When does ionic bonding occur

Answer 1

Metal + non metal
Electron transferred

Question 2

When does covalent bonding occur

Answer 2

When does covalent bonding occur

Question 3

When does metallic bonding occur

Answer 3

Metal and metal
Electron pooled

Question 4

Why do chemical bonds occur

Answer 4

As they lower the potential energy between charged particles that constitute atoms
Potential energy : The stored desire between bonding atoms to repel each other as when two nuclei are pushed together protons are pushed together which repel

Question 5

Compare electronegativity of ionic and covalent bonds increasing

Answer 5

Pure covalent (equally shared)-polar covalent (unequally shared )-Ionic transferred

Question 6

What occurs during ionic bond

Answer 6

The metal loses an electron electron due to low ionisation energy :energy required to remove an electron )
The non metal gains an electron due to high electron affinity

Question 7

What’s ionisation energy of cation -metal to lose electron

Answer 7

Ionisation energy is endothermic

Question 8

What is the acceptance of an electron by non metal

Answer 8

Exothermic

Question 9

Which is larger ionisation energy or acceptance of an electron

Answer 9

Ionisation energy is larger then acceptance of electron
However heat formation of ionic compound is generally an exothermic value

Question 10

What’s the energy difference due to

Answer 10

Energy difference is due to formation of highly ordered structure known as crystal ionic structure

Question 11

Where are valence electrons

Answer 11

Valence electrons are the outermost electrons in an atom

Question 12

What does Lewis theory say

Answer 12

Electrons are transferred from one atom to another forming ions . One atom must lose a valence electron whilst other must gain

Question 13

What are elements with low ionisation energy known as

Answer 13

Electropositive

Question 14

What are elements which require electrons more readily known as

Answer 14

Electronegative

Question 15

What are properties of ionic compounds

Answer 15

Larger ion, weaker attraction and hence
lower lattice energy.
• Larger charge, stronger attraction and
hence higher lattice energy.
• Ionic compounds have high melting points (and boiling points).
• All ionic compounds are solids at room temperature.
• Hard and brittle crystalline solids – many are soluble in water.

Question 16

What’s the Lewis theory applied to covalent bonds

Answer 16

The Octet rule still applies, but now the
atoms achieve their octet by sharing
electrons.
* A bond consists of a shared pair of
electrons.

Question 17

How does chlorine create covalent bonds

Answer 17

Cl + Cl  Cl2
Chlorine has seven valence electrons (3s2 3p5)
Sharing of the unpaired 3p electrons  filled outer shells

Question 18

What are electrons which aren’t shared known as

Answer 18

Electrons that are not shared between
atoms are called lone pairs of electrons

Question 19

What’s the shape of molecule determined by (covalent bonding )

Answer 19

The shape of the molecule (covalent
bonding) using this theory is explained by
electrostatic repulsion between electron-
pair bonds and also lone pairs.

Question 20

What pattern do elements in first period tend to follow

Answer 20

C = 4 bonds and no lone pairs.
• N = 3 bonds and 1 lone pair.
• O=2 bonds and 2 lone pairs.
• H = 1 bond, no lone pairs.
• Halogens = 1 bond and 3 lone pairs

Question 21

What’s a polar covalent bond

Answer 21

Covalent bonding between two different
atoms, e.g. hydrogen and chlorine gives rise to
a covalent bond where the two electrons
(bond) are shared unequally.
• We have a polar covalent bond.
• The polar covalent bond has a polarity, i.e. one
end of the bond has a small positive charge
(hydrogen; relatively electron deficient),
whilst the other end has a small negative
charge (chlorine; relatively electron rich)

Question 22

What are some examples of polar covalent bonds

Answer 22

HCL H2O NH3

These molecules have a dipole

Question 23

What are examples of electronegative elements

Answer 23

Chlorine
Florine
Bromine
Oxygen
Nitrogen

Question 24

Calculation for size of dipole

Answer 24

Size of dipole indicated by dipole moment (µ)

µ = e x d
where e = magnitude of charge on an atom (δ+ or δ-)
and d = distance between the two charges
The unit of m is the debye (D)