We can write the whole configuration:
{Kr} 5s1 4d5
To find this element, you can use the periodic table (most of them have the electronic configuration of the atoms)
The whole configuration would be:
1s2
2s2 2p6
3s2 3p6 3d10
4s2 4p6 4d5
5s1
This configuration is from Mo, molybdenum, Z = 42
Answer: Mo, molybdenum
