The number of electrons,protons, neutron in a species are `18,16 `and `16` respectively. Assigns proper symbols

Explanation

the atomic number is equal to number of protons = 16. the element is sulphur (s).
Atomic mass number = number of protons + number of neutrons = 16 + 16 = 32
species is not neutral as the number of protons is not equal to electrons . It is anion (negatively charged ) with charge equal to excess electrons = 18 - 16 =2 .
symbol is `._(16)^(32)S^(2-)`
note : before using the notation `._(Z)^(A)X` ,find out whether the species is a netral atom. a cation or an anion. if it is a neutral atom , equatoion (2.3) is valid , i.e number of protons = number of electrons = atoms number . if the species is an ion , determine whether the number of protons are larger (cartion , postive ion ) or smaller ( anion , negative ion) than the number of elctrons . number of neutrons is always given by A-Z , whether the species is neutral or ion.