An element is a substance that is made entirely from one type of atom. For example, the element hydrogen is made from atoms containing a single proton and a single electron. If you change the number of protons an atom has, you change the type of element it is
Or
el·e·ment
/ˈeləmənt/

Learn to pronounce
noun
1 1.
a part or aspect of something abstract, especially one that is essential or characteristic
