Octet Rule Practice

Chapter 6 Section 2: Covalent Bonding and Molecular Compounds

by Abby Fancsali

Multiple Choice

Review: What is the term for a mutual attraction between the nuclei and valence electrons of different atoms

• An electronic synchronization

• An element

• Covalent

• Chemical Bond

Multiple Choice

Which type of bonding has the equal sharing of electron pairs between two atoms?

• Ionic

• Covalent

Multiple Choice

Which type of bonding has one atom completely give up an electron to another?

• Ionic

• Covalent

​Introduction

• ​Molecule: a neutral group of atoms that are held together by covalent bonds

  • ​Most Chemical compounds are made up of molecules

  • ​can consist of two or more atoms of the same element or two or more different atoms

    • ​Diatomic molecule: A molecule containing only two atoms

• ​Molecular Compound: a chemical compound whose simplest units are molecules

​Formulas

• ​Chemical formula: indicates the relative numbers of atoms in each kind in a chemical compound by using atomic symbols and numerical super scripts

  • Example: Water = H₂O

  • ​Also known as a molecular formula

    • ​Shows the types and number of atoms combined in a single molecule of a molecular compound

​Formation a of Covalent Bond

• ​Remember: Chemical bonds have lower potential energy

• ​Think about 2 hydrogen atoms

  • ​One proton one electron in each

  • ​The proton in one attracts the electron in the other

    • ​at some distance the attraction of the proton and electron will be equal to the repulsion of the two electrons, and the atoms will "move together"

​Characteristics of a Covalent Bond

• ​At the bottom point of the valley, there is a balance between the two atoms, where the electron clouds overlap bonding the two together

  • ​Valence electron moves between the two atoms

• ​Bond length: the average distance between two bonded atoms

• ​Bond Energy: the energy required to break a chemical bond and form isolated atoms

​The Octet Rule

• ​Recall: Noble Gases are stable and exist freely in nature

  • ​Outer s and p orbitals completely filled

    • ​2+6=8

• ​Other main group atoms can "fill" their outermost orbitals by sharing electrons through covalent bonds

• ​The Octet Rule: Chemical compounds tend to form so that each atom has an octet (8) electrons in their highest occupied energy level

​Exceptions to the Octet Rule

• ​Most main-group elements follow the octet rule, but some exceptions

  • ​Hydrogen-only has two electrons

  • ​Boron: only has three electrons individually, six when it bonds with itself

  • ​Other elements can bond to have more than eight of they are bonding with d-block elements

Multiple Choice

Give me the vocabulary Word for the following definition: a neutral group of atoms that are held together by covalent bonds

• atom bonds

• an octet

• a diatome

• molecule

Multiple Choice

How many atoms are in a diatomic molecule?

• 1

• 2

• 3

• 8

​Electron-Dot Notation

• ​Electron-Dot Notation: shows only the valence electrons of an atom, indicated by dots around the element symbol

  • ​Remember: Valence electrons are anything after your last p⁶

​Sample Problem on the Board

• ​Write the electron Dot Notations for Hydrogen and Nitrogen

​Sample Problem on the Board

• ​Write the electron Dot Notations for Hydrogen and Nitrogen

  • ​Step 1: how many electrons do each of the elements have

​Sample Problem on the Board

• ​Write the electron Dot Notations for Hydrogen and Nitrogen

  • ​Step 1: how many valence electrons do each of the elements have

    • ​Hydrogen: 1

    • ​Nitrogen: 5

Multiple Choice

How many atoms are in a diatomic molecule

• 1

• 2

• 3

• 4

Multiple Choice

"Chemical compounds tend to form so that each atom has an octet (8) electrons in their highest occupied energy level" is known as what

• The Octet Rule

• The Rule of 8

• The Electronic Octave