A what neutral noble-gas atom has the same electron

Question

A monatomic ion with a 1- charge has the electron configuration 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶. 

(a) What neutral noble-gas atom has the same electron configuration?

(b) What is the monatomic ion with a 1- charge that has this configuration?

(c) Write the symbol of an ion with a 2+ charge that is isoelectronic with the species in (a) and (b).