Question

drag the ions together in such a way as to make a rectangle, from top down, in the \build model\ portion of the table below, then fill in the rest of the table. see the sample completed table here:

compound name: magnesium oxide
built model:
cation to anion ratio: ? : ?
compound formula*: ?_? ?_?

*if only one ion is needed in a formula, it is left off, but for this practice you will need to type in the quantity, even a 1.

Explanation:

⚡ Using what you learned: formation of ionic and covalent bonds

Step 1: Determine the Cation to Anion Ratio

To form a neutral ionic compound, the total positive charge from the cations must balance the total negative charge from the anions.

• Cation: Magnesium ion, \(\text{Mg}^{2+}\) (charge of \(+2\))
• Anion: Oxide ion, \(\text{O}^{2-}\) (charge of \(-2\))

Since one \(\text{Mg}^{2+}\) ion balances one \(\text{O}^{2-}\) ion exactly:

$$ (+2) + (-2) = 0 $$

The ratio of magnesium ions to oxide ions is 1 : 1.

Step 2: Determine the Compound Formula

Using the 1:1 ratio, we combine the chemical symbols. The prompt notes that for this specific practice, you must write the quantity even if it is 1:

• Cation symbol and quantity: \(\text{Mg}_1\)
• Anion symbol and quantity: \(\text{O}_1\)

Combining them gives the formula: \(\text{Mg}_1\text{O}_1\).

Answer:

• cation to anion ratio: 1 : 1
• Compound formula: \(\text{Mg}_1\text{O}_1\)