Even atoms are made of smaller particles. In the center there is nucleus which is made of proton and neutron. On the edge there are electrons which can have many layers and configurations. These particles cometogether in different numbers to form different elements.
->Hydrogen (H) atom is made of 1 electron and 1 proton.
->If we double the amount and add 2 neutrons we get Helium (He).
->If we triple that we will get Carbon (C).
Thus we will get all the 94 elements naturally found on earth. Among which, heaviest element is plutonium. There are 94 elements naturally found on earth which are fundamental building block of everything, includinglife.
Human body contains around 7octanium atoms. That is 7000000000000000000000000000 atoms. 7 followed by 27 zeros.
Helium has 2 electrons, 2 protons and 2 neutrons.