Fundamental Flashcards
Atoms
Simplest particle that substances are made from – contain protons, neutrons and electrons.
Have no overall charge as they have equal number of protons and electrons
Element
A substance made of only one type of atom.
Protons
+1 charged particle in the nucleus of an atom. It also has a relative mass of 1
Neutron
Zero charged particle in the nucleus of an atom. It also has a relative mass of 1
Electrons
-1 charged particles that orbit the nucleus in shells (energy levels). It also has a relative mass of 1/2000
Atomic (proton) number
The number of protons an element has. All atoms of the same element have the same number of protons. (Also the number of electrons for atoms)
Mass number
The sum of the protons and neutrons in an atom.
Shells (energy level)
Electron shells hold electrons. The first shell (nearest the nucleus) holds 2, then the next one 8, 8, 2
Group
Columns in the periodic table. Elements in the same group have the same number of electrons in their outer shell (energy level).
Noble gases
This is group 0 in the periodic table. They are unreactive because their outer shells are full.
Ions
- An atom that has gained or lost electrons. Those that gain electrons become a negative ion and those that lose electrons become a positive ion.
- They are charged
- They have a full outer shell
Compounds
When more than one type of atom is chemically bonded together during a chemical reaction.
Reactants
The substances that react together in a chemical reaction.
Products
The substances that are produced during a chemical reaction.
Conservation of mass
Total mass of the reactant = total mass of the products as atoms are not destroyed in reactions
