Would you expect each of the following atoms to gain or lose electrons when forming ions? What i

Would you expect each of the following atoms to gain or lose...

Key Concepts

Standard Oxidation States

Each element typically exhibits common oxidation states that are characteristic of its group. For example, alkaline metals typically form +1 ions, and alkaline earth metals typically form +2 ions due to the loss of their valence electrons. On the other hand, elements such as halogens often form -1 ions by gaining an electron. Recognizing these standard states helps in predicting the ionic charge that an atom is most likely to adopt during chemical reactions.

Periodic Trends and Periodic Table Position

The position of an element in the periodic table helps determine whether it will tend to lose or gain electrons when forming ions. Elements on the left side and in the center are typically metals and will lose electrons to achieve a noble gas electron configuration, while elements on the right side of the table are nonmetals that tend to gain electrons. This concept is crucial in predicting ion formation by considering the element’s group and period, which inform its valence electron count and overall reactivity.

Ion Formation for Stability

Atoms form ions by either losing or gaining electrons to achieve a more stable electron configuration, usually that of the nearest noble gas. This process, known as ionization, is driven by the desire for a complete valence shell. Typically, metals lose electrons to form positively charged ions (cations), and nonmetals gain electrons to form negatively charged ions (anions).

Metallic versus Nonmetallic Behavior

Metallic elements, which are generally found on the left and in the middle of the periodic table, tend to lose electrons during ion formation due to their lower ionization energies and larger atomic radii. In contrast, nonmetals, commonly located on the right side of the table, possess higher electron affinities and tend to gain electrons. This distinction is a fundamental principle in understanding the chemical behavior of different elements.

Transcript

00:01 All right, to this question, we are given a number of atoms and we are asked to predict whether they will gain or lose electrons when they form ions.

00:09 So first up, we have radon.

00:12 Now, the first step to answering a question like this is to find it on the periodic table.

00:18 Sorry, it's not radon, it's radium.

00:20 It's over here, right there.

00:22 It's in group 2a.

00:24 That means it has two valence electrons.

00:26 Now remember, items in group 2a like to lose their electrons.

00:31 So that they can form a stable octet.

00:33 If radium loses its two electrons, it'll have the same configuration as radon.

00:42 So we would expect radium to form an ra2 minus ion 2 -2 -plus.

00:50 Because it loses electrons, so it will have more protons than electrons, so it'll have a positive charge.

00:56 There we go.