1. Some elements like noble gases do not have the tendency to combine with others or even amongst themselves because they have a stable electronic configuration of duplet or octet. Therefore, they do not have the tendency to lose or gain or share electrons. Therefore, they occur in free state.
2. While most of the elements like hydrogen, oxygen, sodium, chlorine etc. are active elements. These elements have incompletely filled outermost orbits and hence show the tendency to lose or gain or share electrons in a chemical change. Therefore, they occur in combined state.
2. While most of the elements like hydrogen, oxygen, sodium, chlorine etc. are active elements. These elements have incompletely filled outermost orbits and hence show the tendency to lose or gain or share electrons in a chemical change. Therefore, they occur in combined state.