Physics

• Atomic number

  Represents the number of protons in the nucleus of an atom (Z)
• Mass

  The number of protons and neutrons in an atom (A)
• Atom

  The smallest particle of matter that can exist on its own
• Element

  The simplest type of a pure substance that can’t be broken down into simpler substances
• Molecule

  Pure substance made up of one more elements which is chemically bonded
• Diatomic molecule

  A molecule consisting of two atoms of the same type
• Compound

  Pure substance made up of two more different types of elements whose atoms are bonded in a fixed ratio by chemical reactions
• Ion

  A single atom or group of atoms with a positive or negative charge
• Covalent chemical bond

  Sharing of valence electrons by two non-metallic atoms
• Orbital

  An area in an atom where there is a high possibility of finding an electron
• Subatomic particles

  Protons, neutrons, electrons
• Valence electrons

  Electrons that an atom can gain or lose that occur in the outer orbital
• Valency

  The bonding possibility of an atom
• A formula unit

  The lowest integer ratio represented by an iconic bond
• A compound can be broken down by

  Electrolysis
• Diatomic molecules

  H2

  Cl2

  Br2

  I2

  F2

  O2

  N2
• Quantity

  A property that can be measured and described using a number or unit