Which of the following correctly describes the Lewis dot structure for the BeH2 molecule?

• A. Beryllium is bonded to two hydrogen atoms with single bonds, and there are two lone pairs on each hydrogen.
• B. Beryllium is bonded to two hydrogen atoms with double bonds, and there are two lone pairs on beryllium.
• C. Beryllium is bonded to two hydrogen atoms with single bonds, and there are no lone pairs on beryllium.
• D. Beryllium is bonded to one hydrogen atom with a single bond and has three lone pairs.

Answer: (C)

Verified step by step guidance

1. Step 1: Determine the total number of valence electrons in the BeH2 molecule. Beryllium (Be) has 2 valence electrons, and each hydrogen (H) has 1 valence electron, so total valence electrons = 2 + 2(1) = 4.
2. Step 2: Arrange the atoms with beryllium as the central atom bonded to two hydrogen atoms. Since Be is less electronegative, it will be the central atom.
3. Step 3: Form single bonds between beryllium and each hydrogen atom. Each single bond consists of 2 electrons, so 2 bonds use 4 electrons, which accounts for all valence electrons.
4. Step 4: Check for lone pairs on each atom. Since all 4 valence electrons are used in bonding, there are no lone pairs on beryllium or hydrogen atoms.
5. Step 5: Confirm the octet rule or duet rule. Hydrogen atoms follow the duet rule and have 2 electrons each from the single bond, and beryllium has only 4 electrons around it, which is typical for Be in such compounds.