Molecular Structure and Geometry
Unit Overview: For students to learn the properties and rules of or molecular structures. They will use their knowledge in chemical bonding to draw Lewis Structures of the molecular compounds. The students will then be able to determine the molecular geometry of the compound from the Lewis Structure.
Throughout the unit, I achieved to learn more about molecular Structure and geometry. I understand the concept of the different shapes, lone pairs of electrons, and drawing a Lewis structure.
Personal Achievement
Enduring Understanding:
The 3 Main Types of Chemical Bonding:
1)Covalent bond- involves sharing a pair of electrons. Electrons in a covalent bond are equally “owned” by both atoms.
2)Metallic - Electrical conductivity, Thermal conductivity, malleability, ductility, shiny appearance. In a metal, the vacant orbitals in the atom's’ outer energy levels overlap to allows the outer electrons of the atoms to move freely.
3)Ionic bonding- metals and nonmetals, stronger than covalent and polar covalent, give up electron to other atoms. Combination of negative and positive ions that the positive and negative charges are equal.
There are two different types of bonds which are ionic and covalent.
Nonpolar-covalent bond:Electronegativity between 0-0.3, bonding electrons are equally attracted to both bonded items
Polar covalent bond:Electronegativity between 0.3-1.7, bonding electrons shared between two atoms are held closely by one atoms.
Ionic bond: Electronegativity between 1.7-3.3.
Steps of Drawing a Lewis Structure
1)Find the total number of valence electrons then add all them
2)Find how many electron each element needs to be stable.
3)Determine the number of bonds in the molecule. Take the total number that is needed to be stable -- the total number that the molecule has / that by two since a bond only need of two electrons.
4)Choose a central atom, especially the one with least electronegativity(except Carbon). Hydrogen will never be the central atom as it only need 2 electrons to be stable.
5)Draw the connecting lines, connect the line to different elements from the central atom.
6)You can create a double bond by connecting 2 lines instead of 4 dots.
Molecular Geometry Models-This can help you identify the molecular geometry of each structures
Demonstrates the understanding of chemical bonds
I think that I had fully understanding about the 3 main types of chemical bonding by identifies its properties and the range (0.0-0.3,0.3-1.7,1.7-3.3)
Develops reading literacy in science
I still need to learn more about understanding this unit by reading because I’m not fully understand about the lewis structure by reading the steps, making me confused leading to incorrect lewis structure. Anyway, I can improve this by practicing drawing lewis structure and write down the steps in my own words.
Weakness
Strengths
We use M&Ms and Pretzels to make structures
