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

Explain Mendeleev’s periodic table

Answer 6

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

Question 7

Explain the modern periodic table

Answer 7

• Ordered by relative atomic mass
• Gaps filled in

Question 8

Name the properties of metals

Answer 8

• Good conductors
• Malleable
• Dense
• High melting points

Question 9

What is ionic bonding between?

Answer 9

Between oppositely charged ions

Question 10

What is covalent bonding between?

Answer 10

Between two non-metals

Question 11

What is metallic bonding between?

Answer 11

Between metals / alloys

Question 12

How are ionic compounds held together?

Answer 12

Strong electrostatic forces

Question 13

Why does ____ conduct electricity?

Answer 13

Delocalised electrons that are free to move across the structure

Question 14

Describe the properties of giant covalent structures

Answer 14

• High melting points
• Insoluble
• Hard
• Electrical insulators

Question 15

Describe the properties of giant ionic lattices

Answer 15

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

Question 16

Describe the bonding of small molecules

Answer 16

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

Question 17

Describe the properties of small molecules

Answer 17

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

Question 18

Describe the bonding in polymers

Answer 18

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

Question 19

Why are alloys harder than pure metals?

Answer 19

• In pure metals, atoms are arranged in layers, so they can slide over each other easily
• In alloys, atoms of the other element disrupt these layers, stops sliding

Question 20

Describe the structure and bonding of graphite

Answer 20

• 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 21

What is graphene used for?

Answer 21

Electronics

Question 22

What are fullerenes used for?

Answer 22

Electronics, material, and medicine

Question 23

What are nanoparticles?

Answer 23

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

Question 24

What are nanoparticles used for?

Answer 24

Medicine
Electronics
Sun cream
Deodorant

Question 25

What is a compound?

Answer 25

Two or more chemicals chemically combined in fixed proportions

Question 26

Describe the Bohr model and how it came about

Answer 26

Electrons orbit the nucleus at specific distances Came from alpha scattering experiment

Question 27

Who discovered neutrons?

Answer 27

James Chadwick

Question 28

What is the radius of an atom?

Answer 28

0.1 nm

Question 29

How do you convert nm to mm?

Answer 29

1 nm = 0.000001 mm 1 mm = 1,000,000 nm

Question 30

What is the radius of a nucleus?

Answer 30

1 x 10^-14 m

Question 31

How much of an atom does the nucleus make up?

Answer 31

1/10000

Question 32

Do isotopes of an element have the same chemical properties?

Answer 32

Yes, because their electronic structure is the same

Question 33

How do calculate relative atomic mass (from abundance)

Answer 33

(Mass x Abundance) + (Mass x Abundance) / 2

Question 34

What happens to electrons in metallic bonding?

Answer 34

Delocalised electrons are shared

Question 35

What happens to electrons in covalent bonding?

Answer 35

They are shared

Question 36

What happens to electrons in ionic bonding?

Answer 36

They are given away

Question 37

Describe three properties of alkali metals

Answer 37

- Soft - Low density - 1 electron in outer shell

Question 38

Alkali + Water --> ??

Answer 38

Salt + Hydrogen

Question 39

How does boiling point change going down group 0?

Answer 39

Increases

Question 40

How are ionic lattices held together?

Answer 40

Electrostatic forces

Question 41

What are some properties of ionic compounds?

Answer 41

High boiling points Don't conduct electricity except when in molten or aqueous form

Question 42

What are nanotubes?

Answer 42

Allotrope of carbon,

Question 43

What are fullerines?

Answer 43

Hollow shaped molecules E.g. Buckminsterfullerene

Question 44

How big are nanoparticles?

Answer 44

1-100 nm

Question 45

How big are fine particles?

Answer 45

100-2500 nm

Question 46

How big are coarse particles?

Answer 46

1 x 10^-5 m and above