Gaining and losing electrons

Now consider the chlorine atom in sodium chloride. The neutral chlorine atom has acquired a negative charge by gaining an electron. Because it has unequal numbers of protons and electrons, it s now an ion, represented like this CL. And 

Here are some extra tidbits about ions for your chemistry reading pleasure  

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Electron carrier. A protein or coenzyme that can reversibly gain and lose electrons and that serves the function of carrying electrons from one site to another. 

The physical properties of the elements, such as melting point, boiling point and density are related to the atomic radius of the elements. Also, the atomic radius directly affects the ability of an atom to gain and lose electrons. The atomic radius is practically defined by assuming the shape of the atom as a sphere. The atomic radius is the distance between the nucleus and the outermost electron. But it is impossible to measure the atomic radius by separating the atoms from each other. Atomic Radius within a Group... 

Identify those atoms gaining and losing electrons ... 

In ionic bonding, atoms gain and lose electrons in order to achieve a noble gas electron configuration. Here s how Lewis symbols show this electron gain and loss in the ionic bonding of sodium chloride ... 

If we could follow the iron atoms in this reaction as it proceeds, we would learn that they gain and lose electrons and are dissolved in water to different extents at different times (Figure 4.1). 

To allow an atomic orbital to both gain and lose electrons, it was considered desirable to use the average of these two expressions consequently, in CNDO/2, the one-electron integral is defined as... 

It is by no means obvious which species are gaining and losing electrons in these reactions. 

In an electrically neutral atom, or an atom in which the number of positive charges equals the number of negative charges, the number of protons must equal the number of electrons. Thus, for a neutral atom, the atomic number is not only the number of protons in an atom, but it is also the number of electrons. An atom may gain and lose electrons, and that is why the number of electrons is not an identifying characteristic for an element like the number of protons is. An atom caimot lose or gain protons. The particle that results from... 

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