In an atom there is a nuclues in the middle of the atom, It contains Protons and neutrons, it has a positive charge because of protons. The electrons move around the nuclues, they're negatively charged, they're tiny but cover a lot of space, they have virtually no mass.
Proton has a mass of 1 and is +1 charge
Neurton has a mass of 1 and has no charge
Electron has a mass of very small often 0 and has a charge of -1
Number of protons usually equals number of electrons. If some electrons are added or removed, the atom becomes charged and is then an ion.
23 is the mass number which is the total number of protons and neutrons
11 is the atomic number which equals the number of protons
To get the number of neutrons, just subtract the atomic number from the mass number.
Atoms of the same element all have the same number of protons - so atoms of different elements have different number of protons.
The atomic number tells you how many protons there are.
Elements and Compounds
Elements have only one type of atom e.g Copper, Aluminium, Irons etc.
Compounds are chemically bonded for example; Carbon dioxide was made from Carbon + Oxygen ---> Carbon Dioxide
Compounds are formed when two or more elements chemically react together. It can be difficult to separate them, the properties of compounds can be different to properties of original elements.
When Iron and sulfur react together they form Iron sulfide, this compound is a grey lump which doesn't have any properties like either iron or sulfur.
Isotopes are different atomic forms of the same element which have the same number of protons but a different number of neutrons. If isotopes had different proton number, they'd be a different element. An example of an isotope would be carbon-12 and carbon-14 which are used for carbon dating.
Proton number = 6 Proton number = 6
Electron number = 6 Electron number = 6
Neutron number = 6 Neutron number = 8