Review Flashcards
Define a physical change of a substance.
A change of substances that does not alter the chemical properties of the substances
example of reversible reactions?
hydrated and anhydrous copper(II) Sulfate and Cobalt(II) Chloride
What is a nucleon number?
Total number of protons and neutrons in the nucleus.
All diatomic molecules
H, N, F, O, I, C, Br
What are isotopes?
Same number of protons, different number of neutrons
Why do isotopes share similar chemical properties?
They have the same number of electrons in the valence shell.
What is a homologous series?
A series of chemical compounds with similar chemical properties and with the same functional group.
Describe the general physical properties of metals as solids.
High MP and BP, good electrical and heat conductors, malleable
Why can metals conduct heat and electricity?
Sea of delocalised electrons
What is an alloy?
A mixture of a metal with another metal/non-metal substance (e.g steel)
What is steel made out of?
Iron and carbon
Explain why alloys are stronger than pure metals.
The atoms with different sizes disrupt the regular arrangement of metal and this prevents the metal layers from sliding over each other.
removing impurities (slag) from hematite
CaCO3
Name of a compound that contains iron oxide
Haematite
Name of aluminium ore
Bauxite
Name of copper ore
Malachite
What is a displacement?
When a less reactive substance is replaced by a more reactive substance
the trend of density of Alkali Metals
It gets less dense as it goes down the table
The trend of reactivity of Alkali Metals
It gets stronger as it goes down the table
Name 3 main substances for fertilisers
Nitrogen, Phosphorous, Potassium
Why is Nitrogen used in fertiliser?
Required to produce protein which is essential for growth of plants
Why is chlorine used in water treatment?
disinfection
Effect of acid rain
chemical weathering
What is galvanisation
Coating steel with a layer of zinc to prevent rusting
Methods to prevent rusting
painting, oil, galvanising, sacrificial protection
