Part 1 - The Importance Of Metals

Question 1

What are the main characteristics of metals?

Answer 1

Dense
Lustrous (shiny) 
Good conductors of heat 
Good conductors of electricity 
Can be shaped by physical forces

Question 2

What are the 2 main ways metals can be shaped by physical forces?

Answer 2

Can be deformed under tensile stress e.g. By stretching - a property known as ductility

Deformed under compressive stress, e.g. By hammering into thin sheets - a property known as malleability

Question 3

What is the definition of malleability?

Answer 3

The property of something that can be worked or shaped or hammered under pressure without breaking

Question 4

What is the definition of ductility?

Answer 4

The ability of a material to deform plastically without fracturing. Measured by elongation or reduction of an area in a tensile test, by height of cupping in an erichsen test, or by other means.

Question 5

What is ppm?

Answer 5

Parts per million

Question 6

How do you calculate parts per million from a percentage?

Answer 6

If you have the percentage then you have it as a fraction.

E.g. 0.012/100

You can therefore work this out in how many parts per million by multiplying by 10

120/100000

Question 7

How is a billion expressed in scientific notation?

Answer 7

10^9

Question 8

What is ppb?

Answer 8

Parts per billion

Question 9

What are alloys?

Answer 9

Alloys are blends of one metallic element with one or more others
E.g. Alloy of copper and tin

Question 10

What are brass, steep and stainless steel made of?

Answer 10

These are all alloys

Brass - copper and zinc

Steel- manly iron and also contains carbon and other smaller amounts of other elements

Stainless steel- steel with a sizeable portion of nickel and chromium

Question 11

What is the unity of purity for gold?

Answer 11

Karat

Question 12

How many karats make up a while in terms of units for gold?

Answer 12

24

1/24 is one unit of gold

Question 13

What is a lattice structure?

Answer 13

It is an ongoing arrangement of metal atoms in a three-dimensional regular ordered pattern

Question 14

How are nuclei and electrons arranged in metals compared to other materials?

Answer 14

The electrons in the outer shells do not remain in proximity of a specific nucleus.

In bulk metals, these electrons, rather than being associated with any particular metal atom, can be thought to be part of a shared sea of electrons that move freely.

Question 15

What are delocalised electrons?

Answer 15

They are electrons that move freely across atoms.

They do not stay in proximity to a specific nucleus

Question 16

What is metallic bonding?

Answer 16

It is the attraction between delocalised electrons and the positively charged nuclei.

Question 17

Why do metals have high melting temperatures?

Answer 17

The metallic bonding is strong and occurs in all directions. Breaking this attraction is difficult, and this is the reason that metals have high melting temperatures.

Question 18

Why are metals good conductors of heat and electricity?

Answer 18

Because of the freely moving electrons, they facilitate the transfer of charge or heat through the material

Question 19

What is an electric current?

Answer 19

It is the flow of negatively charged electrons through a conductor.

Question 20

What is voltage?

Answer 20

In a battery it is considered as the ‘push’ exerted on electrons moving around the circuit.

Question 21

How do delocalised electrons help a metal with its malleability?

Answer 21

The bonding occurs in every direction throughout the metal enabling atoms to roll easily over each other without breaking any bonds when stress is applied.

Question 22

What is the number of a shell containing electrons also known as?

Answer 22

Principal quantum number

n

Question 23

How can you identify a metal when it is impart to a flame?

Answer 23

By the colour change

Question 24

As an electron moves outwards from the nucleus (so as the principal quantum number increases) what happens to the energy of the electron?

Answer 24

It also increases

Question 25

What is a continuous spectrum?

Answer 25

It is when visible light can be split by a prism into an uninterrupted band of colours

Question 26

What is an emission spectrum?

Answer 26

It is the continuous spectrum or pattern of bright lines or bands seen when the electromagnetic radiation emitted by a substance is passed into a spectrometer. The spectrum is characteristic of emitting substance and type of excitation to which is subjected.

Question 27

What is bioaccumulation?

Answer 27

It is the accumulation of substances inside an organism over time.

The concentration of metals within the food chain. Microbes, plants, animals consume and absorb metals in water that can come from sewage, pollution and run off. The concentration of these metals increase as they go up the food chain.

Question 28

What metals are attracted to a magnet?

Answer 28

Iron, nickel, cobalt

Question 29

What metals play an important role in biological systems?

Answer 29

Iron - is essential for transporting oxygen in blood and tissues

Calcium - provides strengths to our bones

Sodium/potassium maintain different concentrations inside and outside of our cells

Zinc is also required for many essential enzymatic reactions (digestion of proteins)

Question 30

What are trace elements?

Answer 30

Metals that occur at really low levels in our body

Question 31

How does the transition of electrons result in emission spectra?

Answer 31

Transitions of electrons from excited states to lower energy levels result in emission spectra

Question 32

What is emission spectra?

Answer 32

It is the basis of simple flame tears for metal salts