Answer:
Ra, 88
Ru, 44
Cr, 24
Explanation:
i
the remaining mass number is 224(228 - 4), and it's atomic number is 88(90 - 2). The element is Radium, Ra
ii
the remaining mass number is 98(98 - 0), and it's atomic number is 44(45 - 1). The element is Ruthenium, Ru
iii
The remaining mass number is 52(52 - 0), and it's atomic number is 24(23 - -1). The element is Chromium, Cr
