Help on Atoms!?

Question

in an atom, how is the electron, neutron, and proton amount determined?

and what does it mean when you have something like

Mg 2+ does that mean it has 2 extra protons? But if the # of protons equals the atomic number (12), then why does it have 12 protons, 10 electrons, and 12 neutrons? why did the protons stay the same but the electrons decreased? or am i doing this wrong?

Answer 1

Any atom cannot increase the number of protons at its will if it is not radioactive.
Mg 2+ means there are two less electrons in the atom which is resulting in the net positive charge.
An atom can accept or donate or share electrons to reach a lower energy state. When electronegative species like halogens approach Mg, it donates two of its outer electrons to the atoms, and so exists as the cation Mg2+. In this state, it still has the same number of protons and neutrons. There is absolutely no change in the nucleus. The only change is in the electron cloud.
This gives the net positive charge to the ion.

Answer 2

there is generally equal protons and electrons or it is charged. neutrons can be varied but it may make the atom unstable.

Mg 2+is positively charged magnesium.
it losses 2 electrons which orbit the nucleus(the protons and neutrons)
originally 12 electrons(- charged) balanced the charge of 12 protons(+ Charged). when 2 electrons are lost they no longer counter the protons and therefore the atom has a positive charge of 2(if it lost 3 electrons it would be 3+, if it gained and electron(say it now had 13)it would be -1

Answer 3

Ya, I think you are doing this wrong? The atom as a whole is electrically neutral -- that means, the # of protons and electrons in an atom are equal! There may be a change in the # of Neutrons instead...

Answer 4

I read Mg2+ as "Magnesium has a valence of +2"

Mg has 12 protons, 12 neutrons, and 12 electrons. It has an innermost shell of 2 electrons, a second shell composed of 8 electrons, and a partial outer shell of 2 electrons which are available to form chemical bonds. These 2 outer electrons are easily stripped away, leaving an ion with a charge of +2
H, F, and Cl "want" another electron to fill their outer shells. O wants 2 electrons to fill its outer shell, so these can be written H1-, F1-, Cl1-, and O2-

The upshot is that you will find common "ionic" compounds of Mg as MgH2, MgF2, MgCl2, and MgO. Other, more complicated compounds can be formed, but I've already been long-winded enough.

Hope this helps.

Answer 5

¹²(Mg) is the magnisium atom wich have 12 electron,12 proton and 12 neutron
24
the electrons are distributed in energy orbitals in the for 2,8,2 and to get stable the atom lose 2 electrons to combine with a (-2) atom

Answer 6

Take a look and read the info on Wiki, should help you