CaCO3 + 2KCL ⇒ CaCl2 + K2CO3
It is balanced as so based on the charges given on the periodic table and polyatomic ions.
Calcium has the charge of 2 but CO3 also shares the same charge, thus cancelling that out.
Potassium has a charge of 1 while Chlorine also shares a charge of 1, also cancelling it out.
Thus, if it performs a double replacement reaction, they would take these charges to the new elements that do not cancel out their charges.
Therefore, we need the coefficient of 2 in front of Potassium Chloride in order to balance the equation as on the products side of the equation, Potassium and Chlorine both have a subscript of 2.
Hope this helps!
Phosphorus has 16 neutrons. Phosphorous is 15 on the periodic table, which means that the atomic number (number of protons) of phosphorous is 15.
For more info: https://study.com/academy/answer/what-is-the-number-of-neutrons-in-phosphorus.html
