How does the addition and subtraction of subatomic particles affect the atom?

Adding or removing neutrons from the nucleus are how isotopes are created. Protons carry a positive electrical charge and they alone determine the charge of the nucleus. Adding or removing protons from the nucleus changes the charge of the nucleus and changes that atom's atomic number.

Explanation:

if you add or subtract a proton from the nucleus, you create a new element. If you add or subtract a neutron from the nucleus, you create a new isotope of the same element you started with. In a neutral atom, the number of positively charged protons in the nucleus is equal to the number of orbiting electrons

they are made of gases.

they have a spherical shape.

they make energy through fusion.

let that person have a turn to speak : )