Isotopes

• isotopes are atoms of the same element that have the same atomic number but a different mass number
• isotopes have the same chemical properties, ie all isotopes of hydrogen have the same chemical behaviour
• If atoms of the same elements can have a different number of neutrons, there mass must be also different
• Chemists use an average mass of the atoms in an element for calculations, taking into account the different isotopes and their relevant abundance
• This average mass is called the "relative atomic mass"