Which has a larger radius, Mg or Mg+2? Explain why. Thanks ! I think its Mg+2 but im not sure why.
Lets look at the structure.
In the nucleus it's 12 protons and 12 neutrons.
The outside shells are
2...8 ...2
|...| ...|
|...|....|
The numbers are the electrons in the outside shells and those | and
|
|
are supposed to be shells.
What I've drawn is the Mg ATOM. If you make the Mg^+2 ion, we remove the two outside electrons. Now, which one, the atom or the ion is smaller and which is larger.?
so that means the ion is smaller because your removing the 2 outside electrons ?
yes.
To determine which ion, Mg or Mg+2, has a larger radius, we need to consider the electron configuration and the charge of the ions.
The atomic radius generally decreases as we move across a period from left to right in the periodic table. This is due to the increasing nuclear charge, which attracts the electrons more strongly, causing the atomic size to decrease.
However, when we compare ions, it's essential to consider the electron configuration as well. Magnesium (Mg) has an atomic number of 12, with a neutral charge. Its electron configuration is 1s² 2s² 2p⁶ 3s².
When magnesium forms an ion, it loses two electrons to achieve a stable noble gas configuration. Therefore, Mg+2 has the electron configuration 1s² 2s² 2p⁶, like neon (Ne).
Now, let's analyze why Mg+2 has a larger radius than Mg:
1. Ion charge: Mg has a 2+ charge, while Mg+2 has a 2+ charge. Since they have the same charge, the difference in radius will not be determined by the charge.
2. Electron configuration: Mg+2 has lost two electrons compared to Mg. As a result, Mg+2 experiences a decrease in electron-electron repulsion, allowing the remaining electrons to be pulled closer to the nucleus, thereby reducing the atomic radius.
Therefore, Mg+2 has a smaller atomic radius than Mg. In other words, Mg has a larger radius than Mg+2.
To summarize, when an atom loses electrons to form an ion, it becomes smaller due to the increased pulling force of the positive nucleus on the remaining electrons. Thus, the ion with the higher charge (Mg+2) will have a smaller radius than the neutral atom (Mg).