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Presented by Kesler Science
Molecules Created by Kesler Science – More 5E lessons at KeslerScience.com Presented by Kesler Science
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Essential Questions: What are the basic differences of elements, molecules, and compounds? What determines the number of molecules in a chemical equation?
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Lets Review – Molecules
The basic building blocks for all matter is an atom. An element is a substance consisting of a single type of atom. © KeslerScience.com
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Molecules Molecules Examples of molecules O2 – oxygen O3 - ozone
The smallest fundamental unit of a chemical compound Made up of two or more atoms bonded together The atoms can be the same or different. Examples of molecules O2 – oxygen O3 - ozone H2O – water CO2 - carbon dioxide H2SO4 – sulfuric acid © KeslerScience.com
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Molecules Needs 2 electrons to have a full outer shell 6 valence electrons in an oxygen atom Molecules Formed when two or more atoms bond together chemically Bonds can form between same atoms or different atoms. These bonds form as a result of the sharing or exchange of valence electrons among atoms. Oxygen atoms Oxygen molecule O2 Valence electrons are always looking to fill the outer most electron layer. By sharing electrons both oxygen atoms now have complete outer shells. Two oxygen atoms bonding by sharing electrons © KeslerScience.com
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Elements Molecules Examples of elements O – oxygen H - hydrogen
The most basic form of a material. One or more atoms of the same type. Elements are listed on the periodic table. Examples of elements O – oxygen H - hydrogen Elements that naturally exist as molecules O2 – oxygen O3 - ozone © KeslerScience.com
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NaCl Compound Molecules Elements Compound
A chemical substance formed when two or more different elements bond in a specific proportion. The elements lose their individual chemical properties and the compound has new properties. Explosive solid Poisonous gas Compound NaCl © KeslerScience.com
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Molecules Compound Chemical bonds are a result of the sharing or exchanging electrons among the atoms. A molecule is the smallest unit that still keeps the properties of the compound. If the compound could be broken any further, the parts would be elements with different properties. 2 Hydrogen atoms 1 Oxygen atom Water Molecule Properties: both are gases neither conducts electricity Properties: liquid conducts electricity © KeslerScience.com
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Quick INB Action – Molecules Practice
Elements Compounds 1. Quickly sketch the 3 circles 2. Draw each object in the correct circle. © KeslerScience.com
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Quick Action – Molecules Practice
Grab a partner and let’s practice. Is it an element, molecule, compound, or combination? Formula Molecule Compound Element Both Compound and Molecule Both Element and Molecule O2 NaCl CH4 H2 H Atoms elements and compounds This would be a good short video to show at this time. Write a rule that you can follow for determining the difference in a compound and a molecule. Here is a hint… All ___________ can be ___________, but….. © KeslerScience.com
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Quick Action – Molecules Practice
Grab a partner and let’s practice. Is it an element, molecule, compound, or combination? Formula Molecule Compound Element Both Compound and Molecule Both Element and Molecule O2 NaCl CH4 H2 H Atoms elements and compounds This would be a good short video to show at this time. © KeslerScience.com
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H2O H +H + O Chemical Formula Molecules
The recipe for a chemical substance Tells the number of atoms of each element in a compound or molecule Uses symbols for the elements present and subscripts (small numbers) to indicate the number of elements Ex. H2O - water H2O H +H + O subscript H H O 2 Hydrogen atoms and 1 oxygen atom © KeslerScience.com
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2H2 + O2 → 2H2O Chemical Equation Molecules
A shorthand that scientists use to describe a chemical reaction The number in front of the element symbol (called a coefficient) indicates the number of molecules. If no coefficient appears in front of a molecule, we interpret this as meaning one. Coefficient 2H2 + O2 → 2H2O 2 hydrogen molecules + 1 oxygen molecules = 2 water molecules © KeslerScience.com
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Quick Action – Molecules Practice
Grab a partner and let’s practice. Count the molecules in each balanced equation. 1. CH4 + 2O CO2 + 2H _____ CH4 _______ O2 _______ CO2 _________H20 2. 2Fe +3Cl FeCl _____ Fe _____ Cl2 _____ FeCl3 3. P4O10 + H2O H3PO _____ P4O10 ______ H2O _____ H3PO4 1 2 1 2 2 3 2 1 1 4 © KeslerScience.com
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Check for Understanding
Can You- Describe the differences in an element, a molecule, and a compound? Determine the number of molecules in a balanced equation? Clear up any confusion and answer questions. © KeslerScience.com
