Topic 2 - Bonding, Structure And Properties Of Matter

Question 1

Covelent bonds

Answer 1

• When non-metal atoms bond together, they share pairs of electrons to make covalent bonds
• Each atom involved generally makes enough covalent bonds to fill up its outer shell
• Positively charged nuclei of bonded atoms are attracted to the shared pair of electrons by electromagnetic forces, making covalent bonds very strong

Question 2

Covalent bonding, where does it happen?

Answer 2

In compounds of non-metals (e.g. H2O) and in non-metal elements (e.g. Cl2)

Question 3

Where do atoms share their electrons?

Answer 3

Atoms only share electrons in their outer shells (highest energy levels)

Question 4

Each single covalent bond…

Answer 4

Provides one extra shared electron for each atom

Question 5

3 ways you can draw covalent bonds

Answer 5

• dot and cross diagrams
• displayed formula
• 3D model

Question 6

The dot and cross diagrams

Answer 6

• Shows the bonding in covalent compounds

- Electrons drawn in overlap between the outer orbitals of two atoms are shared between those atoms

Question 7

Why are dot and cross diagrams useful?

Answer 7

For showing which atoms the electrons in a covalent bond come from

Question 8

Disadvantage of dot and cross diagrams?

Answer 8

They don’t show the relative sizes of the atoms, or how the atoms are arranged in space

Question 9

Displayed formula

Answer 9

Shows covalent bonds as single lines between the atoms

Question 10

Advantage to displayed formula

Answer 10

A great way of showing HOW atoms are connected in LARGE molecules

Question 11

Disadvantage to displayed formula

Answer 11

Doesn’t show the 3D structure of the molecule, or which atoms the electrons in the covalent bond have come from