Unit 3: Chemistry in Society Flashcards
Elements essential in Fertilisers
Nitrogen (N)
Phosphorus (P)
Potassium (K)
Natural Fertilisers
Decay of dead plants + animals
Decay of plant + animal waste
Synthetic Fertilisers
Ammonia (Haber Process)
Nitric Acid (Ostwald Process)
Haber Process
Nitrogen + Hydrogen ⇔ Amonia
450ºC
200 atm
Iron Catalyst
Solubility
Fertilisers are usually very soluble and can be washed into rivers and lochs, increasing pollution
Ammonia
Invisible gas with a characterstic smell. Very soluble and produces an alkaline solution. Released when ammonium compounds are heated with an alkali
Ammonia + Acid
Forms ammonium salts
Nitric Acid
Formed when brown gas nitrogen dioxide dissolves in water
Nitrogen Monoxide
Formed from nitrogen and oxygen in a lightning storm
Heavy Elements
Formed from lighter elements in stars
Radioactive Elements
Become more stable by giving out alpha, beta or gamma radiation
Nuclear Equations
Written to describe nuclear reactions
Half-Life
Time taken for half of the nuclei of a particular isotope to decay
Use of Radioactive Isotopes
In medicine Cobalt-60 is used to kill cancer cells
Alpha Particles (α)
Made of 2 protons and 2 neutrons (identical to helium nucleus). Heavy and Positively charged
Beta Particle (β)
Made of 1 very fast moving electron. Light and negatively charged
Gamma Ray (γ)
Part of the E-M spectrum. Has no mass, travels at the speed of light and has a very high frequency so a very high energy
Ionisation
When an atom loses or gains an electron giving it a charge
Alpha Penetration
Stopped by a few cm of air or a thin sheet of paper
Beta Penetration
Stopped by a thin sheet of aluminium
Gamma Penetration
Stopped by Lead or Concrete
All metals
Conduct electricity when solid or liquid
Metals are good conductors of
Heat
Density
How heavy a metal is
Malleability
How easily a metals shape is changed
Metal + Oxygen
→ Metal Oxides
Metal + Water
→Hydrogen + Metal Hydroxide
Metal + Acid
→Hydrogen + Salt