Answer: [He] 2s² 2p¹
Explanation:
1) B is boron
2) Atomic number of boron is 5, meaning that it has 5 protons and 5 electrons.
3) So, the ground state electron configuration is 1s² 2s² 2p¹
4) Using the noble-gas shorthand notation means that you start with the configuration of the noble gas previous to the element.
In this case, the noble gas that is before B is He.
So, the noble-gas shorthand notation for B is [He] 2s² 2p¹