Question

question 1 (2 points)
the molecular formula for water is h₂o. the first step to getting the structural formula is to find the central atom. the two criteria for finding the central atom are that it should be the least abundant atom, and the atom that can form the most number of bonds.
the least abundant atom is 1.
from the periodic table, h can form only 2 bond, while o can form 3 bonds.
thus, the central atom in water is predicted to be 4.
the 5 are then placed around the central atom.
a. hydrogen b. oxygen c. 0 d. 1 e. 2 f. 3 g. 4 h. 5

Explanation:

• For the first blank, in \(H_2O\), oxygen (\(O\)) is less abundant than hydrogen (\(H\)) as there is 1 \(O\) atom and 2 \(H\) atoms.
• For the second blank, from the periodic table, hydrogen (\(H\)) has 1 valence electron and can form 1 bond.
• For the third blank, oxygen (\(O\)) has 6 valence electrons and needs 2 more to complete its octet, so it can form 2 bonds.
• For the fourth blank, since \(O\) is less abundant and can form more bonds (compared to \(H\)), it is the central atom.
• For the fifth blank, the \(H\) atoms are placed around the central \(O\) atom.

Answer:

1. B. Oxygen
2. D. 1
3. E. 2
4. B. Oxygen
5. A. Hydrogen