Question

what is the formula for a beryllium atom achieves noble gas configuration?
be+1
be+2
be-2
be-1

Explanation:

Step1: Recall beryllium's electron - configuration

Beryllium (Be) has an atomic number of 4. Its electron - configuration is 1s²2s².

Step2: Determine how to achieve noble - gas configuration

Noble gases have a full outer shell. Beryllium can lose 2 electrons to have the electron - configuration of helium (1s²), which is a noble - gas configuration. When it loses 2 electrons, it forms a cation with a + 2 charge.

Answer:

Be⁺²