What is the formula for K plus combined with CO3 charge 2?

The formula for potassium combined with the carbonate ion (CO₃^2-) is K₂CO₃.

To understand this, we start by looking at the components involved. Potassium (K) has a charge of +1, while the carbonate ion (CO₃) carries a charge of -2. To achieve a neutral compound, we must balance the charges.

Since each potassium ion contributes +1 charge, we need two potassium ions to balance the -2 charge from one carbonate ion:

• 2 (K⁺¹) = +2
• 1 (CO₃^2-) = -2

Therefore, the overall formula is K₂CO₃, indicating that two potassium ions combine with one carbonate ion to form potassium carbonate.