The first one is the answer
isotopes of an atom have different number of neutrons . the number of protons are not different in isotopes of an atom
Answer:
wind
Explanation:
wind is a natural and renewable resource
Atoms are the smallest form of the substance. examples of atoms are in elemental forms such as copper, helium, silver. Diatomic molecules are made up of identical atoms. Examples are I2.. F2 and Br2. Formula units are those compounds that are made up of two or more elements such as -No2, KMnO4,<span>C3H8, MgCl2, HgBr2, Ba(OH)2</span>
Answer:
About 60.
Explanation:
Mendeleev knew of 63 elements. He wrote their properties on cards and arranged them in order of atomic mass.
That's how he discovered that the properties of elements are periodic functions of their atomic masses.