Question

how many electrons will selenium need to gain or lose to be left with a full outer shell of valence electrons? * 2 points se: lose 1 gain 2 lose 3 gain 4 lose 5 gain 6 lose 7 gain 8

Explanation:

Step1: Determine selenium's valence electrons

Selenium (Se) is in group 16 of the periodic table and has 6 valence electrons.

Step2: Recall octet - rule

Atoms tend to gain, lose or share electrons to have 8 valence electrons (a full outer shell).

Step3: Calculate the number of electrons to gain or lose

Since Se has 6 valence electrons, it needs to gain 2 electrons to reach 8 valence electrons.

Answer:

gain 2