covalent bonding

Question 1

covalent bond

Answer 1

electrostatic attraction between two nuclei and a shared pair of electrons

Question 2

dative covalent bond

Answer 2

covalent bond where shared electron pair comes from only one participating atom

Question 3

lone pair

Answer 3

pair of electrons on an atom’s outer shell that is not being used in a bond

Question 4

electronegativity

Answer 4

ability of an element to attract a shared pair of electrons to itself within a covalent bond

Question 5

how would metals form covalent bonds?

Answer 5

• their ionisation energies are very high
• electronegativity difference between the metal and the non-metal it is bonding to is smaller than 2

Question 6

orbital theory

Answer 6

covalent bonds are formed when orbitals, each containing one electron, overlap. this forms a new region in space where an an electron pair can be found - new molecular orbitals are formed
- the greater the overlap, the stronger the bond
- more shared pairs = bigger overlap

Question 7

where can sigma bonds form?

Answer 7

• s + s orbital
• s + p orbital
• p + p orbital

Question 8

pi bonds

Answer 8

double bond between two atoms - one of them is a pi bond. it is formed by ‘above and below’ overlap of p orbitals

Question 9

what affects the strength of a covalent bond?

Answer 9

atomic radii - if it’s smaller, nuclei and shared pair of electrons are closer = stronger attraction
nuclear charge + shielding - increased nuclear charge, decreased shielding = stronger attraction
electronegativity