+ and - ions

Moderators: Chem_Mod, Chem_Admin

Sara Richmond 2K
Posts: 110
Joined: Fri Aug 30, 2019 12:16 am

+ and - ions

Postby Sara Richmond 2K » Sat Oct 26, 2019 5:31 pm

I had a questions on a chemistry concept relating to determining the electron configuration of an ion- do you move left or right on the periodic table for charge? 
For example: 
1. Is the electron configuration of Fe^+ the same as the electron configuration of Mn (move left) or the same as Co (move right) 
2. Is the electron configuration of Fe^- the same as the electron configuration of Mn (move left) or same as Co (move right) 
3. Does the statement Fe^+ mean that Fe lost or gained an electron? 
4. Does the statement Fe^- mean that Fe lost or gained an electron? 


Please answer all 4 questions so I can better understand this confusing material. I keep mixing them up in my head.

Sanjana K - 2F
Posts: 102
Joined: Sat Sep 07, 2019 12:17 am
Been upvoted: 1 time

Re: + and - ions

Postby Sanjana K - 2F » Sat Oct 26, 2019 5:55 pm

1. Fe^+ has the same config as Mn.
2. Fe^- has the same config as Co.
3. Fe^+ means that Fe lost an electron.
4. Fe^- means that Fe gained an electron.

You can think of Fe as initially a neutral molecule [Fe]. But by adding a minus sign after it, as [Fe]^-, you're saying that it has one additional electron (1 unit of negative charge). By adding a plus sign after it, as [Fe]+, you're saying that it is actually a positive version /ion of Fe, so it lost an electron.
Last edited by Sanjana K - 2F on Sat Oct 26, 2019 5:59 pm, edited 1 time in total.

Deena Doan 2F
Posts: 100
Joined: Sat Aug 17, 2019 12:17 am

Re: + and - ions

Postby Deena Doan 2F » Sat Oct 26, 2019 5:56 pm

1) move left
2) move right
3) If it has a positive charge (aka a cation), it loses an electron.
4) If it has a negative charge (aka an anion), it gains an electron.

Sofia Barker 2C
Posts: 101
Joined: Wed Sep 18, 2019 12:21 am

Re: + and - ions

Postby Sofia Barker 2C » Sun Oct 27, 2019 4:38 pm

Fe + has the same electron configuration as Mn because Fe + has lost an electron (26 e- minus 1 e- = 25 e-) and thus has 25, the same number as Manganese does. The "+" sign following Fe denotes this loss of electrons because there is a ratio of 26 protons to 25 electrons, giving iron an overall positive charge.

Fe - has the same electron configuration as Co because Fe - has one more electron than its original state, Fe, and thus has 27 total electrons, which will match the same configuration as the 27 electrons present in Co. The "-" sign indicates that Fe - has a ratio of 27 electrons to 26 protons, giving the atom an overall charge of -1.

I like to think of the "+" and "-" following an atom's symbol as a reference to its charge. A "+" means that an atom has a positive charge, which can only happen when the atom has lost one or more electrons. A "-" means that an atom has a negative charge, which can only happen when the atom has gained one or more electrons. So when you see that an atom of a certain element has a "+", this means that it has the same number of electrons as the element preceding it on the periodic table because elements are in order of increasing number of electrons. This logic can be applied with an atom with the "-" sign because the sign indicates another electron and thus the same number of electrons as the following element (to the right) in the periodic table.


Return to “Ionic & Covalent Bonds”

Who is online

Users browsing this forum: No registered users and 1 guest