Bonding, Strucuture and Properties of Matter Flashcards
1
Q
What is an ion?
A
- Charged particles formed by the loss or gain of electrons to form a stable electronic structure
- Metals - lose electrons to form positive ions.
- Non-Metals - Gain electrons to form negative ions
2
Q
What is the structure of ionic compounds?
A
- Giant ionic lattices
- Forms a regular lattice with strong electrostatic forces of attraction between oppositely charged ions in all directions
3
Q
Properties of ionic compounds
A
- high MP and BP due to strong bonds
- Cannot conduct electricity when solid as ions held in place
- Can conduct electricity when molten
- Some can conduct electricity when dissolved in water
4
Q
What is a simple molecular substance?
A
Molecules containing a few atoms joined together by covalent bonds.
5
Q
Properties of simple molecular substances
A
- Forces of attraction are very weak so MP and BP are very low
- Most are gases or liquids at room temp.
- As they get bigger, the intermolecular force increases and so do MP and BP
- Don’t conduct electricity because they aren’t charged
6
Q
What is metallic bonding?
A
- The electrons in the outer shell of metal ions are delocalised
- Strong forces of electrostatic attraction between positive metal ions and negative electrons.
- The forces of attraction are known as metallic bonding and are very strong.
7
Q
What are nanoparticles?
A
Extremely small particles: diameter between 1-100nm
8
Q
Properties of nanoparticles
A
Large surface area to volume ratio:
- ratio = surface area/volume
- As particles decrease in size the surface area increases in relation to the volume
- Often need less of a material made up of nanoparticles to act as an effective catalyst because of its large surface area.
9
Q
Uses of nanoparticles
A
- Catalysts
- Nanomedicine: is absorbed more easily into the body and can deliver drugs directly to cells.
- Electric circuits for computer chips
- Cosmetics
