Cation Formation

​Cations and Anions

​

Cations

​Some atoms will lose electrons to achieve a stable electron configuration. A positive ion is formed to have an electron configuration similar to that of the nearest noble gas.

​If the last energy level 1, 2 or 3, we must lose an electron

​The last level must be complete

​Na=1s² 2s² 2p⁶ 3s¹

​Example

​Sodium atom

​Sodium ion (Na⁺)

​+=1+

​An ion with a positive charge is called a cation.

Multiple Choice

A potassium atom (K)

1s2 2s2 2p6 3s2 3p6 4s1

• A potassium atom (K) loses 1 electron potassium ion (K+).

• A potassium atom (K) loses 3 electron potassium ion (K3+).

• A potassium atom (K) gain 1 electron potassium ion (K-).

• A potassium atom (K) gain 2 electron potassium ion (K2-).

​ Anions

Some atoms will gain electrons to achieve a stable electron configuration. The negative ion that is formed also has an electron configuration similar to that of the nearest noble gas.​

​If the last energy level 5, 6 or 7, we must gina an electron

​Fluorine atom

​(F)=1s² 2s² 2p⁵

​Example

​fluoride ion (F⁻)

​An ion with a negative charge is called an anion.

​-=1-

Multiple Choice

A nitrogen atom (N)

1s2 2s2 2p3

• A nitrogen atom (N) loses 3 electrons (N3+).

• A nitrogen atom (N) gains 3 electrons (N3−).

• A nitrogen atom (N) gains 3 electrons (N3+).

• A nitrogen atom (N) gains 4 electrons (N4−).

​done by: Ali and Salem

​thank you for play