Chemistry Topic 2

Question 1

Structure of metallic bonding:

Answer 1

-regular rows of positive ions
-strong electrostatic force of attraction
-electrons are free to carry charge through out the metal

Question 2

What is Metallic bonding:

Answer 2

A strong electrostatic attraction between positively charged metal ions and negatively charged electrons

= free to move

Question 3

What are alloys and what happens within them?

Answer 3

-mixtures of metals

-layers of alloys are distorted as they have ions that are different sizes
- cannot slide over eachother anymore —-> makes them harder material

Question 4

What is ionic bonding and what happens within it?

Answer 4

-reaction between a metal and a non-metal

-electrons are transferred from a metal to a non metal to complete a full outer shell

Question 5

Ionic compound:

Answer 5

• giant ionic lattice
• positively and negatively charged ions in a constant ratio
• strong electrostatic force of attraction acting in all directions
• solid at room temperature
• conduct electricity when molten or aqueous

Question 6

What is covalent bonding?

Answer 6

• occurs between non metal ions
• shared pairs of electrons
• small covalent molecules

Question 7

What is a strong covalent bond?

Answer 7

• one that requires a significant amount of energy to break

Question 8

Properties of small covalent molecules:

Answer 8

-usually gases or liquids
-low melting points and boiling points
-weak intermolecular forces between the molecules
- larger molecules have higher melting and boiling points
-cannot conduct electricity because molecules don’t have an overall electric charge

Question 9

What are some examples of small covalent molecules?

Answer 9

-oxygen
-nitrogen
-methane

Question 10

What are polymers?

Answer 10

-molecules with a very long chain of repeating units called monomers
-have strong covalent bonds
-weak intermolecular forces
-solids at room temperature

Question 11

What are giant covalent structures and give examples:

Answer 11

-thousands of atoms bonded together

-diamond:
(one version of carbon) —> every carbon atom in it makes 4 strong covalent bonds = ions cannot slide over each other (hard) - cannot conduct electricity

-graphite:
—> every carbon atom in it makes 3 strong covalent bonds - has 1 electron left over per carbon atom = becomes delocalised electron (free to move) - can conduct electricity even tho it’s a non metal (it is soft and slippery as it has weak forces of attraction) = hexagonal

-Graphene:
—> single layer of graphite- can conduct electricity

-fullerene:
—> type of nano particle (very small) = C60 - 60 carbon atoms joined together

-silica: (not carbon atom)
—> every silicon atom is joined to 4 O2 atoms, every O2 atom is joined to 2 silica atoms = strong covalent bonds - high melting/boiling points. Cannot conduct electricity