WAEC - Physics (2004 - No. 50)
Which of the following representations is correct for an atom X with 28 electrons and 30 neutrons?
\(^{30}_{28} X\)
\(^{28}_{30} X\)
\(^{58}_{30} X\)
\(^{58}_{28} X\)
Vysvětlení
\(X^{A = p + n = 28 + 30 = 58}_{Z = P = E = 28}\)