Topic 1- Key Concepts In Chemistry Flashcards
On the left hand side of an equation are…
The reactants
On the right hand side of an equation are
The products
State symbols
(s) - solid
(l) - liquid
(g) - gas
(aq) - aqueous, dissolved in water
Ammonia formula
Chlorine formula
NH3
Cl2
(The numbers are smaller than the letters and sit below the line when written)
Ammonium, Nitrate, Sulfate, Hydroxide and Carbonate
Formula
NH4 + NO3 - SO4 (2-) OH - CO3 (2-) (The numbers are smaller than the letters and sit below the line when written)
Oxidising
Harm, example and symbol?
Provides oxygen which allows other material to burn more fiercely
Eg. Liquid oxygen
Symbol- circle with flame on top
Harmful
Harm, example and symbol?
Can cause irritation, reddening or blistering of the skin
Eg. Bleach
Symbol- an explanation mark
Environmental hazard
Harm, example and symbol?
Harmful to organisms and to the environment
Eg. Mercury
Symbol- a dead tree and dead fish
Highly flammable
Harm, example and symbol?
Catches fire easily
Eg. Petrol
Symbol- a line with a flame above it
Toxic
Harm, example and symbol?
Can cause death by for example swallowing, breathing in or absorption through the skin
Eg. Hydrogen cyanide
Symbol- skull and cross bones
Corrosive
Harm, example and symbol?
Destroys materials including living tissues (like eyes and skin)
Eg. Concentrated sulfuric acid
Symbol- two test tubes pouring a substance which is decaying a hand and a block object
John Dalton (19th century) described atoms as…
Solid spheres and said that different spheres made up different elements
In 1897 J J Thomson had a new theory called the…
Plum pudding model
His measurements of charge and mass from experiments concluded that an atom must contain even smaller, negatively charged particles- electrons.
Rutherford (1909) had a theory of…
The atom containing mostly empty space and having a positively charged nucleus at the centre
Bohr model showed…
All electrons are contained in a shell
Electrons can only exist in fixed orbits, or shells, nowhere in between
Each shell has a fixed energy
Subatomic particles and their properties
Protons - relative charge is positive (+1) and a relative mass of 1
Neutrons - relative charge is neutral (0) and a relative mass of 1
Electrons - relative charge is negative (-1) and a relative mass of 0.00005
Atoms are neutral because…
The number of electrons is equal to the numbers of protons
In an ion the number of protons…
Does not equal the same number of electrons
Therefore the ion has a charge
The atomic number (bottom number) tells you…
How many protons an atom has
So for a neutral atom the number of electrons will also equal the atomic number
Mass number (top number) tells you…
The total number of protons and neutrons in an atom
To work out the number of neutrons in an atom you…
Mass number - atomic number = neutron number