Basic Atomic Structure L1

Question 1

Why study materials?

Answer 1

So manufacturers know it will:

• perform its function
• continue to perform its function
• can be easily processed
• can be predicted
• cost effective
• environmentally friendly

Question 2

List mechanical properties (9)

Answer 2

Strength- compressive, tensile, shear

Stiffness 
Toughness
Hardness 
Elasticity
Plasticity
Ductility, malleability, brittleness

Question 3

List physical properties (7)

Answer 3

Density
Mp/bp
Glass transition temp
Thermal conductivity, heat capacity, expansion, stability
Electrical conductivity, resistivity, permitivty
Magnetic properties
Optical transparency, refractive index, colour

Question 4

What are the 2 factors affecting properties and some examples of each?

Answer 4

Processing- heat treatment, forming

Environment- corrosion, electric field

Question 5

What is Angstrom scale?

Answer 5

Atomic scale

10^-10m

Question 6

What is the nanoscale?

Answer 6

10^-7 to 10^-9

Molecules, clusters of atoms, crystal structure

Question 7

What is the micro scale?

Answer 7

10^-3 to 10^-7

Grains of material, composite structures

Question 8

What is macro scale?

Answer 8

Large scale observable properties

- eg tensile strength, electrical conductivity

Question 9

Which electrons are most weekly attracted to the nucleus? What does this mean?

Answer 9

The outer ones as they’re further away, meaning they take part in bonding

Question 10

What is Coulomb’s law?

Answer 10

In a vacuum:

F= 1 Q1Q2
———- x ————
4pieE0 r^2

Question 11

Which orbitals do electrons prefer to occupy?

Answer 11

Those closest to the nucleus

Question 12

Give the number of electrons that can occupy each of the following orbitals:
S, p, f, d

Answer 12

S- 2
P- 6
D- 10
F- 14

Question 13

When is 0 energy in terms of electrons and the nucleus?

Answer 13

When an electron is infinite distance from the nucleus

Question 14

What are the 2 basic factors that determine reactivity of an atom?

Answer 14

Atomic number- as it increases the pull on electrons increases do they’re harder to pull from the atom

Electron distance from the nucleus- can be screened by inner electrons so they’re easier to pull away

Question 15

What is the trend in ionisation energy as you go across the periodic table?

Answer 15

General increase across a period, maxima at noble gasses, minima at alkali metals
He has the largest IE