Here's the breakdown of the subatomic particles and their charges in a calcium atom:

* Protons:

* Charge: +1

* Location: Nucleus

* Number: 20 (This is the defining characteristic of calcium - all calcium atoms have 20 protons)

* Neutrons:

* Charge: 0 (Neutral)

* Location: Nucleus

* Number: Varies depending on the isotope of calcium. The most common isotope has 20 neutrons.

* Electrons:

* Charge: -1

* Location: Orbiting the nucleus in electron shells

* Number: 20 (To balance out the 20 positive protons, there are 20 negative electrons)

Key Concept: Atoms are electrically neutral. This means that the total positive charge from the protons is balanced by the total negative charge from the electrons.