You will explore graphic representations of different atoms to discover the relationship between valence electrons, locations on the Periodic Table, and chemical reactivity.
After completing this tutorial, you will be able to complete the following:
Electrons are located in orbitals. No more than two electrons exist at the same time in these spaces. These orbitals exist at various energy levels in an atom. The number and arrangement of electrons in these orbitals determines if the electrons will enter or leave an atom to form bonds. The electrons in the highest available energy level may not be paired, however. Since this is the case, these electrons, also known as valence electrons, need to be gained or lost to fill the orbitals with pairs.
The number of electrons needed to create stable, nonreactive atoms is eight electrons. To achieve this, atoms either gain or lose electrons. This is known as the octet rule. Following this rule, atoms will develop a negative charge if they have more electrons than protons, or develop a positive charge if they have more protons than electrons.
The loss or gain of electrons is determined by the number of electrons present when the atom is neutral. If the element is a metal, its number of valence electrons is small (between one and three); therefore, it has a tendency to lose electrons. If the element is a nonmetal, its number of valence electrons is higher than metals (between five and seven); therefore, it has a tendency to gain electrons. In particular, these atoms with a higher number of valence electrons gain the electrons lost by atoms with fewer valence electrons. When this exchange occurs between two atoms?one metal and one nonmetal?an ionic bond forms.
|Approximate Time||20 Minutes|
|Pre-requisite Concepts||Learners should have a knowledge of electron orbitals and how the filling of these orbitals creates an atoms valence electrons. Learners should also have knowledge of noble gases and how they represent filled energy levels on the Periodic Table.|
|Type of Tutorial||Concept Development|
|Key Vocabulary||atom, chemical reactivity, electron|