What do these symbols mean?
(s):
(l):
(g):
(aq):

(s) : Solide

(I) : Liquid

(g) : gas

(aq) : Aqueous

the correct option is c.

isotopes refers to different forms of the same element with the same atomic number but different mass number as a result of difference in their neutron numbers. isotopes have different relative atomic mass but share the same chemical properties.