No it NEVER EVER EVER EVER changes other wise it would be a completely different element like aluminum .
yes
no. because if the number of protons changes, then the element changes
No because the number of protons can not change. If it does it would then be Oxygen. Think of a proton as an id number or SSN.
Protons = 17, electrons = 18There are two isotopes differing in neutron number only :Cl-35 (75%) having 35-17= 18 neutronsCl-37 (25%) having 37-17= 20 neutrons
Only of isotopes. Calcium is an element. No mixture of chemicals can ever be a single element. The atoms of any element, such as calcium, always have the same number of protons and the same number of electrons. The number of electrons in an atom is the same as the number of protons in that atom. Different Isotopes of an element have different numbers of neutrons in the nucleus, but this doesn't change any of the chemical properties.
The number of electrons can be determined if the overall charge and number of protons are known. If the charge of an atom is neutral, then how ever many protons it has it will also have that number of electrons.
NO
If you take a proton away from an element, the whole element will change. For example, you take away one proton from mercury, then you would have gold. People have tried this for many years but so for it's impossible. If you change the number of protons in a atom, it would change the whole substance.
Protons are not involved in chemical reactions.
No space probe has ever landed on Mercury.
Under normal conditions, i.e. non-ionic, the number of protons is equal to the number of electrons.
There is no evidence that Mercury ever had a moon.