When \\\\(4p\\\\) orbital in any atom are filled completely, the next electron goes in \\\\(5s(n+l=5+0=5)\\\\) not in \\\\(4d(n+l=4+2=6)\\\\),electron first enters into the subshell which is having less \\\\((n+l)\\\\) value (energy). Hence the \\\\(5s\\\\) is filled first than \\\\(4d\\\\).