Lewis Dot Structures Of Atoms And Ions Worksheet printable pdf download

Topic H – Bonding – 01

Block 071

Lewis Dot Structures of Atoms and Ions

PDP Chemistry

Page 1 of 5

Block 071:

NAME: ________________________________

Lewis Dot Structures of Atoms and Ions

Niels Bohr developed a model of atomic structure to explain the observation that certain elements were

highly reactive (like carbon and hydrogen) and others (like helium and argon) were not. In this model

electrons were moving in shells around the nucleus. The electrons always try to be in the lowest energy

shell – the shell closest to the nucleus. As electrons are added, they fill the shells from the lowest to the

highest in terms of energy.

The outermost electrons, the electrons in the highest energy shell, are called

the valence electrons. According to the Quantum model of the atom,

Sodium, which has 11 electrons, has an electron configuration:

The highest occupied energy level is the 3s shell, and it contains one electron,

so sodium is said to have only one valence electron. Similarly, other elements

in the first column of the periodic table have similar configurations, and

therefore also have one valence electron.

You may recall that Mendeleev used

similarities in the properties of elements

to organize his periodic table. The

similarities in behavior between atoms

of the same group is due to the fact that

atoms in the same group have similar

electron configurations, and the same

number of valence electrons. A chart

showing how many valence electrons

each representative element or noble

gas has is found to the right. The

number of valence electrons can be

easily determined from what group an

element is in.

Valence electrons are usually the only electrons used in chemical bonds. Therefore, as a

general rule only the valence electrons are shown in electron dot structures. Electron dot

structures are diagrams that show valence electrons as dots. The inner electrons and the

atomic nuclei are included in the letter symbol for the element being represented. The valence

electrons are spread out around the chemical symbol. It is acceptable to draw the electrons in

any pattern around the symbol, as long as there are no more than two electrons on a side.

Lewis Dot Structures Of Atoms And Ions Worksheet