The abundance of elements in the universe and on earth is a measure of how much in terms of mass or percentage of that element is naturally occurring. Some elements in the universe such as hydrogen and helium, very basic elements make up large amounts of matter in the universe. Where as rare elements like francium and caesium are much less abundant and rare.
Atomic structure is the positively charged nucleus and the negatively charged electrons circling around it, within an atom.
The atomic number of the elements provides information on the number of protons in the nucleus.
Atomic mass refers to the mass of both the protons and neutrons and is always the larger of the two represented in the periodic table.
Isotopes are elements with different numbers of neutrons in the nucleus but the same number of protons.
Ions are atoms or groups of atoms that have either lost or gained electrons so they have a positive or negative charge.
Some elements have to be made in the lab as they cannot exist in the natural world like most elements. These elements sometimes require special conditions and equipment to force them to decay or force two different nuclei together.
Electrons exist in shells around the nucleus and have different configurations and layouts based on the element in the periodic table. Electrons are also very important in bonding.
Atoms make up all matter around us, they are the smallest part of all things. Atoms in the periodic table all have different numbers of protons and are known as elements and they can be combined to make compounds and molecules
By the 1930’s the atom consisted of a proton as a positive area of charge and electrons orbiting it but there was still a piece missing. It was not until 1932 that James Chadwick discovered a particle with the same mass of a proton but no overall charge, the neutron.
The atomic radius is a measure of the distance from the nucleus to the valence electron.