Topic #2: Bonding and structure

Question 1

What are the 3 bond types?

Answer 1

Covalent- sharing electrons
Ionic- giving electrons
Metallic- pulled together by charges

Question 2

When does each bond type occur?

Answer 2

Covelant- Nonmetal and Nonmetal
Ionic- Metal and Nonmetal
Metallic- Metals/alloys

Question 3

Metals that lose electrons become _______ charged ions.

Answer 3

Positively

Question 4

How are ionic compounds (giant ionic lattices) held together?

Answer 4

Strong electrostatic forces of oppositely charged ions

Question 5

Can covalent bonds contain small molecules?

Answer 5

Yes

Question 6

Are covelant bonds strong or weak?

Answer 6

Strong

Question 7

Are polymers covelantly bonded?

Answer 7

Yes

Question 8

What causes the strong metallic bonds?

Answer 8

Free to flow delocalised electrons

Question 9

When do things change state of matter?

Answer 9

Freezing and melting at melting point

Boiling and condensing at the boiling point

Question 10

How does the strength of the bonds affect melting points?

Answer 10

The stronger the bond, more energy is needed to break it (higher melting point)

Question 11

List the 4 state symbols

Answer 11

g - gas
l - liquid
s - solid
aq - aqueous in solution

Question 12

Why are ionic melting points so high?

Answer 12

Many very strong electrostatic forces of attraction are hard to break

Question 13

Why can molten ionic compounds conduct electricity?

Answer 13

The ions are free to move

Question 14

Are boiling points for small molecules high or low, and why?

Answer 14

Low, because only weak intermolecular forces need to be broken, not the covelant bonds.

Question 15

How does molecule size impact intermolecular force strength?

Answer 15

The larger the molecules the stronger the bond

Question 16

Do polymers have high or low melting points?

Answer 16

High- they are large molecules

Question 17

What are the melting points for giant covelant structures like?

Answer 17

High, there are very strong bonds

Question 18

Why are alloys harder than pure metals?

Answer 18

Different size atoms disrupt smooth slidy layers

Question 19

Do all metals have high melting points?

Answer 19

No

Question 20

Why are metals good conductors?

Answer 20

They can carry charge and energy in the delocalised electrons

Question 21

Describe diamond’s structure.

Answer 21

4 hexagonal carbon bonds, very strong, no conduction, high melting point, hard

Question 22

Describe the structure of graphite.

Answer 22

3 Carbon bonds, with one delocalised electron per atom to carry charge. No bonds between layers, soft.

Question 23

What are fullerenes?

Answer 23

Hexagonal carbon structures (can be rings of 5 or 7) made of carbons, useful in nanotechnology

Question 24

What is graphene?

Answer 24

A single layer of graphite, useful in electronics

Question 25

What are the size boundaries for nanoscience?

Answer 25

1-100 nm

Question 26

What are the size of fine and coarse particles?

Answer 26

Fine, 100-2500 nm

Coarse, 2500-10000 nm

Question 27

If the sides of a cube decrease by 10 times what does the surface area to volume ration increase by?

Answer 27

10 times

Question 28

Why use nanoparticles over bulk metal?

Answer 28

Nanoparticles have larger surface areas, meaning less is needed, and they have different properties

Question 29

What can nanoparticles be used for?

Answer 29

Suncreams, electronics, cosmetics, medicine, catalysts and deodorants