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CHEMISTRY-1 CHAPTER 1 CHEMISTRY—THE SCIENCE OF MATTER.
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CHEMISTRY-1CHAPTER 1CHEMISTRY—THE SCIENCE OF MATTER Chemistry is the study of matter and energy. In this chapter, you will examine the physical and chemical properties of matter. You will perform experiments and record data. You will learn how to classify matter as either a pure substance or a mixture. You will also be introduced to the chemical language of symbols and formulas.
is also known as the central science • Chemists are employed in dozens of occupations • Whatever your career choice is, chances are you will need some knowledge of chemistry!!!!
Matter Anything that takes up space and has mass Can be classified as solid, liquid, gas or plasma
What is not matter? • ENERGY, HEAT, LIGHT, ELECTROMAGNETIC WAVES, MAGNETIC FIELDS, IDEAS, ETC. Properties of Matter • Describe the characteristics and behavior of matter, including the changes that matter undergoes
Observing Matter • Macroscopic Observations: Observations made with the 5 senses • Microscopic Observations: Observations made with a microscope • Submicroscopic Observations: Observations of substances so small they cannot even be seen with a microscope Macroscopic Microscopic Submicroscopic
Mass • Units: grams or kilograms • Measured with: Triple Beam Balance
Scientific Model • Thinking device used to explain and represent macroscopic observations. • Important in chemistry because the atom is so small we must study it at a submicroscopic level Scientific model of a water molecule Scientific model of an atom
Quantitative Observation: An observation that involves a numerical value. • Qualitative Observation: Describes the properties of a substance
PURE SUBSTANCE • Matter with the same fixed composition and properties • First Type of Pure Substance • Element • The Periodic Table: A chart that lists the chemical name and chemical symbol for each element • Chemical Symbol: A shorthand abbreviation for the name of an element Aluminum = ___ Tin = ____ Carbon = ____ Xenon = ____
PURE SUBSTANCE • Matter with the same fixed composition and properties • Second Type of Pure Substance • Compound • Chemical Formula: A combination of chemical symbols that show what elements make up a compound and the number of atoms of each element • Subscript: A number written to the lower right of an element symbol to indicate the number of atoms of that NaH2CO3 Mg(OH)2
MIXTURES Two or more elements physically combined.
Homogeneous Mixtures • The prefix “homo-” means “the same” • A mixture that is the same throughout • You cannot see the phases (parts) of the mixture.
Solutions • Solute: The substance being dissolved in a solution • Solvent: The substance that dissolves the solute • Aqueous Solution: A solution in which water is the solvent
Heterogeneous Mixtures • The prefix “hetero” means “different” • A mixture with different compositions throughout • You can see each phase (part) of the mixture
Methods to Separate Mixtures • Filtration: Separates a solid from a liquid
Separating… • Magnet: Separates Fe, Co, or Ni
Separating… • Crystallization: Separates crystalline solids from a saturated liquid
Separating… • Distillation: Separates two or more liquids with different boiling points.
Separating… • Chromatography: Separates different types of liquids
States of Matter • Depends on: • Solid: • Liquid: • Gas:
PLASMA The most common form of matter Free electrons and ions of an element. Energy is needed to strip atoms of their electrons. Plasmas can be steered and controlled by magnetic and electric fields.
PLASMA TV’S • Xenon and Neon in each cell • Intersecting electrodes charged causing electric current through the gas in that cell • Electric current = rapidly flowing charged particles causing the release of UV photons • Photons interact with the phosphor coating giving off colored light Because each cell is lit individually, the image is bright and looks good from almost any angle.
Physical Properties quantitative What are the physical properties represented in the images above? characteristics qualitative
Density To calculate Density Density = Mass ÷ Volume
Chemical Reaction: A Chemical Change • After a chemical reaction: The original substance no longer has the same identity • Chemical reactions can be used to:
Law of Conservation of Matter • Matter cannot be created nor destroyed in a chemical reaction. • Developed by: Antoine Lavoisier • Mathematically: • Mass of the reactants = Mass of the products • (starting materials) (ending materials)
ENERGY IN CHEMICAL REACTIONS • Most chemical reactions involve changes in energy. • The unit for energy is the Joule (J) • This is because bond breaking requires energy and bond forming releases energy. • Almost all chemical reactions either release or absorb energy • This energy flow results in heat, either being absorbed or released.
EXOTHERMICREATIONS • To the touch an exothermic reaction would feel HOT because heat is being released to the surroundings
ENDOTHERMIC REACTIONS • To the touch an endothermic reaction would feel cold because heat is being absorbed from the surroundings.
Law of Conservation of EnergyEnergy cannot be created nor destroyed!
Law of Conservation of EnergyEnergy cannot be created nor destroyed! …or from one kind of energy into another kind. Any situation where energy is transferred from one object to another…
Rube Goldberg Machine Draw your final sketch today. Label all 10 forms of energy associated with your machine. Webster's Dictionary definition of "rube goldberg”: Accomplishing by extremely complex, roundabout means what seemingly could be done simply.
Rube Goldberg Machine Objective:Make a drawing of a Rube Goldberg device of your own creation which includes examples of each of the 10 basic types of energy and 10 different energy changes. 10 energies - these should be clearly labeled and numbered in blue next to where the energy occurs in the drawing. 10 different energy changes - arrows should be drawn connecting each energy in the drawing to the next in red to show how one type of energy is changing into another.