Neon is an element that consists of only one type of atoms and cannot be divided into simpler forms through chemical reactions. For this reason, its formula contains only one chemical symbol of neon which is Ne.
Carbon monoxide is a compound that contains diatomic molecules which consists of carbon and oxygen atoms. For this reason, its formula CO contains two chemical symbols C and O.
Glucose is a compound which consists of carbon, hydrogen and oxygen atoms. For this reason, its formula C6H12O6 contains three chemical symbols C, H and O.
Cobalt is an element that consists of only one type of atoms and cannot be divided into simpler forms through chemical reactions. For this reason, its formula contains only one chemical symbol of cobalt which is Co.
Fluorine is an element that consists of only one type of atoms and cannot be divided into simpler forms through chemical reactions. For this reason, its formula contains only one chemical symbol of fluorine which is F.