Presentation on theme: "Introduction to Matter. Chemistry is the study of matter and how it changes... Matter is anything that has mass and takes up space (or has volume). There."— Presentation transcript:
Chemistry is the study of matter and how it changes... Matter is anything that has mass and takes up space (or has volume). There are 3 topics you have studied which are not matter because they have no mass or volume. What do you think they are? Light Sound Electricity
Atoms Elements Compounds Molecules All compounds are molecules... but not all molecules are compounds!!
ATOMS The smallest particle that has properties of an element is an atom! Atoms are matter! What are the parts of an atom?????
ELEMENTS An element is a substance that cannot be broken down into a simpler substance. Each element has a one or two letter symbol. RELATIVE AMOUNTS OF THE ELEMENTS IN YOUR BODY
COMPOUNDS A compound is a substance made of atoms of more than one element bound together. H2O2H2O2 COO2O2
MOLECULES Molecules are the smallest unit of a substance that exhibit all of the properties characteristic of that substance. H2OH2OO2O2
CHEMICAL FORMULAS A chemical formula is a written way to show what elements and how many atoms of an element are in a compound or molecule. Example: 2 2 stars or I can count that I have four stars I have two to the second power in stars HHH2H2 I can count that I have two atoms of Hydrogen (H) or I can write the chemical formula by writing the symbol for Hydrogen followed by a subscript that shows how many atoms of hydrogen there are
Practice! Two atoms of Oxygen: O2O2 Four atoms of Carbon: C4C4 One atom of Chlorine: Cl One atom of Carbon and two atoms of Oxygen: CO 2 If the chemical formula for a water molecule is H 2 O, what does 3H 2 O mean???
Pure Substances v. Mixtures A pure substance is matter with a fixed composition and definite properties. Compounds can be pure substances A mixture is a combination of more than one pure substance. Which of these are Pure Substances and which are Mixtures?? Cough SyrupWater SugarApple Juice Salt Water Aluminum Moving on...
Classification of Mixtures We can mix solids and liquids or liquids with liquids. If the substances are not uniformly mixed; your substance is a heterogenous mixture. If the substances are uniformly mixed then your substance is a homogeneous mixture. Any part of a system that has uniform composition and properties is called a phase. A homogeneous mixture will have one phase. A heterogeneous mixture will have two or more phases.
When dealing with liquid- liquid mixtures... A mixture with liquids that are miscible will dissolve into each other in various proportions. A mixture with liquids that are immiscible will not mix with one another.