Bonding, Structure, and the Properties of Matter

Question 1

Describe Rutherford’s particle scattering experiment

Answer 1

• He fired alpha particles at thin gold foil in a vacuum
• Most particles passed through
• Some were deflected as they passed through
• Few were deflected straight back

Question 2

What did Rutherford’s experiment help him discover?

Answer 2

• Most of the atom is empty space
• Dense, positively charged nucleus
• Mass concentrated at the centre

Question 3

What did Niels Bohr discover?

Answer 3

That electrons orbit the nucleus at specific distances (energy levels)

Question 4

In what order were the three subatomic particles discovered?

Answer 4

1. Electron
2. Proton
3. Neutron

Question 5

What did James Chadwick discover?

Answer 5

Neutrons

Question 6

What is the radius of an atom?

Answer 6

1 x 10^-10 metres

Question 7

What is the radius of a nucleus?

Answer 7

1 x 10^-14 m

Question 8

Explain Mendeleev’s periodic table

Answer 8

• Ordered by atomic weights (didn’t account for isotopes)
• Left gaps for undiscovered elements

Question 9

Explain the modern periodic table

Answer 9

• Ordered by relative atomic mass
• Gaps filled in

Question 10

Which elements react to form positive ions?

Answer 10

Metals

Question 11

Which elements react to form negative ions?

Answer 11

Non-metals

Question 12

Name the properties of (transition) metals

Answer 12

• Good conductors
• Strong/hard
• Dense
• High melting points

Question 13

What is ionic bonding?

Answer 13

Between oppositely charged ions (giving away electrons)

Question 14

What is covalent bonding?

Answer 14

Between two non-metals (sharing electrons)

Question 15

What is metallic bonding?

Answer 15

Between metals / alloys (sharing delocalised electrons)

Question 16

How are ionic compounds held together?

Answer 16

Strong electrostatic forces

Question 17

Why does ____ conduct electricity?

Answer 17

Delocalised electrons that are free to move through the structure

Question 18

Describe the properties of giant covalent structures

Answer 18

• High melting points
• Insoluble
• Hard
• Electrical insulators

Question 19

Describe the properties of giant ionic lattices

Answer 19

• High melting points
• When (aq) or (l), can conduct electricity as ions are free to move so charge can flow

Question 20

Describe the bonding of small molecules

Answer 20

• Strong covalent bonds hold atoms in a molecule together
• Weak intermolecular forces hold molecules together

Question 21

Describe the properties of small molecules

Answer 21

• Low melting points
• Electrical insulators
• Melting points increase dependent on size of molecules

Question 22

Describe the bonding in polymers

Answer 22

• Atoms covalently bonded
• Molecules are held together by relatively strong intermolecular forces (solid at RTP)

Question 23

Why are alloys harder?

Answer 23

• In pure metals, atoms are arranged in layers, so they’re bent easily
• In alloys, atoms of the other element disrupt these layers

Question 24

Describe the structure and bonding of graphite

Answer 24

• Arranged in layers held together by weak intermolecular forces
• Atoms in layers covalently bonded
• Delocalised electrons (each carbon has 3 bonds and 4 electrons)

Question 25

What is graphene used for?

Answer 25

Electronics

Question 26

What are fullerenes used for?

Answer 26

Electronics, material, and medicine

Question 27

What are nanoparticles?

Answer 27

• Particles 1-100nm in size
• High surface area to volume ratio

Question 28

What are nanoparticles used for?

Answer 28

Medicine, electronics, and cosmetics