[Kr]4d6 ion has 42 electrons. As it is a 3+ ion, the parent atom would have 45 electrons. This would make it Rhodium Rh.
Argon
Rhodium (Rh) forms a 3 plus ion that has the electron configuration Kr4d6. Rhodium has oxidation states of 2,3 and 4, so it can loan out 2, 3 or 4 electrons depending on the circumstances of a chemical reaction.
hafnium
Adding one electron gives the chloride ion which has an octet (it achieves the same electron configuration as argon.
All elements have electrons, when the amount of electrons they have changes they are called ions. They only element that forms an ion with no electrons is Hydrogen (H). To learn more about electrons and ions you should inquire about electron configuration.
Argon
Rhodium (Rh) forms a 3 plus ion that has the electron configuration Kr4d6. Rhodium has oxidation states of 2,3 and 4, so it can loan out 2, 3 or 4 electrons depending on the circumstances of a chemical reaction.
hafnium
Adding one electron gives the chloride ion which has an octet (it achieves the same electron configuration as argon.
All elements have electrons, when the amount of electrons they have changes they are called ions. They only element that forms an ion with no electrons is Hydrogen (H). To learn more about electrons and ions you should inquire about electron configuration.
The ions of elements nitrogen (N3-), oxygen (O2-), and fluorine (F-) will have the same electron configuration as a sodium ion (Na+), which is the same as the electron configuration of the noble gas neon.
Considering the normal calcium ion Ca2+ it has the same electronic configuration as the noble gas Argon.
S
Oxygen
The element chlorine does not have noble gas configuration. But chloride ion formed (when chlorine accepts an electron) has noble gas configuration of argon.
The electron configuration of selenium for a 2- ion is [Kr]4s2.3d10.4p6.
Calcium