Fundamental ideas Flashcards
element
A substance made up of only one type of atom. An element can not be broken down chemically into simpler substance.
atom
The smallest part of an element that can still be recognised as that element.
group
All the elements in each column (labelled 1 to 7 and 0) down the periodic table.
nucleus
The very small and dense central part of an atom which contains protons and neutons.
electron
A tiny particle with negative charge. Electrons orbit the nucleus in atoms or ions.
compound
A substance made when two or more elements are chemically bonded together. For example, water (h20) is a compound made from hydrogen and oxygen.
proton
A tiny positive particle found inside the nucleus of an atom.
neutron
A dense particle found in the nucleus of an atom. It is electrically neutral, carrying no charge.
atomic number
The number of protons ( which equals the number of electrons) in an atom. It is sometimes called the proton number.
mass number
The number of protons plus neutrons in the nucleus of an atom.
energy level
An area in an atom, around the nucleus, where the electrons are found.
shell
An area in an atom, around the nucleus, where the electrons are found.
electronic structure
A set of numbers to show the arrangement of electrons in their shells, for example, the electronic structure of a potassium atom is 2,8,8,1
ionic bond
The electrostatic force of attraction between positively and negatively charged ions.
covalent bond
The attraction between two atoms that share one or more pairs of electrons.
