Question

Write the names of the ions you chose.

List 5 monoatomic ions with their correct superscripts (charges). Note the charge.

Write the names of the ions you chose.

Explain the criss-crossing method of bonding.

Write 3 monoatomic ions and 3 polyatomic ions from your list.

Apply the criss-cross method to determine their superscript numbers (charges). Each ion gets the other ion's superscript number. Place the number on the bottom right corner of the ion's symbol.

Write the formula of the resulting 3 ionic compounds you formed.

Write the name of the 3 compounds you formed. (Hint: The compound name is taken from the names of the ions you used.)

Answer 1

To write formulas for ionic compounds, the criss-cross method involves using the charge of each ion as the subscript for the other ion. Examples include NaCl (Sodium Chloride), CaO (Calcium Oxide), and Al(NO3)3 (Aluminum Nitrate), demonstrating the crossing of charges to balance the compound.

Step-by-step explanation:

To write the correct formulas for ionic compounds, we use the criss-cross method, which involves crossing over the numerical value of each ion's charge to become the subscript for the other ion in the compound. Here are five monoatomic ions with their charges:

• Sodium ion (Na+) - Charge: +1
• Chloride ion (Cl−) - Charge: -1
• Calcium ion (Ca2+) - Charge: +2
• Oxide ion (O2−) - Charge: -2
• Aluminum ion (Al3+) - Charge: +3

Now let's use three monoatomic ions (Sodium, Calcium, and Aluminum ion) and three polyatomic ions (Chloride, Oxide, Nitrate NO3−) to form ionic compounds using the criss-cross method:

1. Sodium ion (Na+) and Chloride ion (Cl−) cross to form NaCl, Sodium Chloride.
2. Calcium ion (Ca2+) and Oxide ion (O2−) cross to form CaO, Calcium Oxide.
3. Aluminum ion (Al3+) and Nitrate ion (NO3−) cross to form Al(NO3)3, Aluminum Nitrate.

As observed, each ion adopts the charge of the other as a subscript (ignoring the sign), with subscripts '1' typically omitted. Also, notice how with polyatomic ions like the nitrate ion, we use parentheses when more than one polyatomic ion is needed to balance the overall charge, hence, Al(NO3)3 for Aluminum Nitrate.