Metals, Non-metals, Mettaloids and radioactivity Flashcards
What are some properties of non-metals?
Not malleable and ductile like metals are
They tend to be brittle and break if put under pressure
Have low melting and boiling points
Several are gas at room temperature
Are non-conductors and will not allow an electric current to pass through them easily
Where are non-metals found?
On the right hand side of the periodic table (except for hydrogen). They are separated from the metals by the metalloids.
What are metalloids?
They have properties between the metals and non-metals and are often called semi-conductors.
How many metalloids are there?
8
Where are metalloids found?
Between the metals and non-metals in a staircase arrangement
Examples and uses of metalloids?
Boron (B) used in products like Borax.
Arsenic (As) used in poisons.
Antimony (Sb) used in flame-retardants.
Examples of non-metals
Phosphorus (P) used to make match-heads.
Sulphur (S) used to make gunpowder and sulphuric acid.
Fluorine (F) used in small quantities in toothpaste.
Where are metals found?
On the left side of the periodic table with the exception of hydrogen.
Properties of metals
Lustrous (have a shiny appearance).
Have high melting points
Mostly solids at room temperature (except Mercury)
Good conductors of electricity
Can be beaten into a sheet (called malleability) al
Can be drawn into a wire (called ductility)
Metals are also good conductors of heat
Examples of metals and their uses
Aluminium (Al) used to make cans, food wrap, power-lines, roofing materials, aircraft and boat hulls.
Copper (Symbol Cu) used to make water pipes and tanks, electric wiring and roofing.
Lead (Symbol Pb) used in plumbing, flashing, leadlight and in solder.
What are metal alloys?
Different metals melted together and cooled to form a solid that has properties of all the metals it’s made of or totally different properties altogether.
Examples of alloys and their uses
Steel (carbon and iron) used in building products and car bodies.
Cupronickel (copper and nickel) used in coins.
Bronze (copper and tin) used in water taps and statues.
What is radioactivity?
Radioactivity is the act of emitting radiation spontaneously.
The three types of radioactive decay
Alpha Decay (⍺) Beta Decay (β) Gamma Decay (γ)
How many protons and neutrons do alpha particles have
2 protons and 2 neutrons, the same as a helium nucleus (He atom with no electrons)
Alpha particles have a mass of 4
A charge of +2
Properties of beta particles.
Beta particles have a mass of 1/1837 (~1/2000)
Have a charge of -1
Properties of gamma particles.
Gamma Rays are energy and have no mass at all (mass of 0)
Have no charge (charge of 0)
Travel at speed of light.
Penetrating powers of alpha decay?
Alpha particles (α) High mass and move comparatively slowly.
Can be stopped by a few centimetres of air.
Have a high charge but low energy
Won’t penetrate skin but are very dangerous if swallowed.
Penetrating powers of beta decay?
Beta particles (β) small mass and move fast. Can be stopped by a few millimetres of Aluminium. Have a small charge but high energy. Can be dangerous at medium range.
Uses of radioactive materials
Smoke detectors
Thickness detectors for paper, foil, plastic etc…
Sterilisation of food, hospital equipment etc…
Radioactive dating
Radioactive tracers in medicine
Weld checking
Cancer treatment (radiography)
Penetrating powers of gamma decay?
Gamma Rays (γ) no mass and move at the speed of light.
Can be stopped by thick lead or concrete.
Have very high energy.
Are dangerous at a distance.
What causes radioactivity?
The atomic nucleus is unstable. It will give up some energy in order to shift to a more stable configuration.
