2.2 Electrons, Bonding and Structure

Question 1

What is an orbital?

Answer 1

A region of around the nucleus that can hold up to two electrons, with opposite spins.

Question 2

How many electrons in an s-orbital?

Answer 2

2

Question 3

How many electrons in p-orbitals?

Answer 3

6

Question 4

How many electrons in d-orbitals?

Answer 4

10

Question 5

How many electrons in f-orbitals?

Answer 5

14

Question 6

What is electronegativity?

Answer 6

The ability of an atom to attract the bonding electrons in a covalent bond.

Question 7

What is the principal quantum number?

Answer 7

It represents the overall energy of each orbital

Question 8

What is an ionic bond?

Answer 8

An electrostatic attraction between two oppositely charged ions.

Question 9

Define covalent bond.

Answer 9

The strong electrostatic attraction between a shared pair of electrons and the nuclei of bonded atoms.

Question 10

Which covalent compounds are special.

Answer 10

Boron trifluoride and sulphur hexafluoride.

Question 11

What is average bond elthalpy?

Answer 11

The energy required to break a covalent bond

Question 12

What is dative covalent bonding?

Answer 12

Where both electrons come from one atom.

Question 13

Angle of linear molecules.

Answer 13

180

Question 14

Angle of trigonal planar

Answer 14

120

Question 15

Angle of tetrahedral

Answer 15

109.5

Question 16

Angle of trigonal pyramidal

Answer 16

107

Question 17

And of nonlinear

Answer 17

104.5

Question 18

Angle of trigonal bipyramidal (five electron pairs)

Answer 18

120 and 90

Question 19

And of octahedral.

Answer 19

90

Question 20

What is electronegativity?

Answer 20

An atoms ability to attract an electron pair in a covalent bond

Question 21

Most electronegative elements in order.

Answer 21

F, O, Cl, N, C, H

Question 22

What is a dipole?

Answer 22

A difference in charge between two atoms caused by a shift in the electron density of the bond.

Question 23

What does the Pauling scale measure?

Answer 23

Electronegativity of an atom.

Question 24

What is a dative covalent bond?

Answer 24

A shared pair of electrons

Where both electrons are donated by one atom

Question 25

How does the number of election pairs allow us to predict bond shape?

Answer 25

Pairs of electrons surround a central atom repel
Shape is determined by the number of bond pairs
AND
The number of lone pairs

Question 26

What are the two types of intermolecular force?

Answer 26

hydrogen bonding

Van der Waals forces

Question 27

What do Van der Waals forces include?

Answer 27

• permanent dipole -induced dipole
• permanent dipole - permanent dipole
• london (dispersion) forces

Question 28

How do permanent induced dipoles arise?

Answer 28

molecule with permanent dipole causes non polar molecule to become slightly charged and attracts it

Question 29

What are London (dispersion) forces?

Answer 29

• two non-polar
  -instantaneous dipoles formed due to random movement of electrons
  induces dipoles in neighbouring molecules

Question 30

What does the size of London forces depend on?

Answer 30

increases with increasing numbers of electrons

Question 31

Example of giant covalent lattices

Answer 31

diamond
graphite
SiO2

Question 32

Are giant covalent lattices soluble?

Answer 32

no

Question 33

What molecules have hydrogen bonding?

Answer 33

N O F