- Life Sciences
two or more forms of a particular chemical element, that have the same number of protons in the nucleus but have different numbers of neutrons in the nucleus. The different possible versions of each element are called isotopes.
a sticky film that forms on the enamel of teeth. It is made up of small food particles, saliva...
the volume of air that is inhaled and exhaled during normal breathing.
the instrument that measures the volume of air entering and leaving the lungs.