1 / 28

Scientific Process/Matter

Scientific Process/Matter. Unit 1. Chemistry –. the study of the composition of matter and the changes it undergoes. There are 5 main branches of chemistry:. Organic -. The study of compounds that contain carbon. Inorganic -. The study of compounds which, in general, do not.

aderes
Télécharger la présentation

Scientific Process/Matter

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Scientific Process/Matter Unit 1

  2. Chemistry – the study of the composition of matter and the changes it undergoes There are 5 main branches of chemistry: Organic - The study of compounds that contain carbon Inorganic - The study of compounds which, in general, do not Biochemistry - The study of chemical processes which take place in organisms Analytical - The study of the composition of matter Physical - The study of reaction rates and mechanisms, as well as the energy transfer which occurs during a reaction

  3. Pure vs. Applied • Pure Chemistry – the pursuit of chemical knowledge for its own sake • The chemist doesn’t expect that there will be any immediate practical use for the knowledge. • Ex. – Studying the composition of desks. • Applied Chemistry – research that is directed toward a practical goal or application. • The chemist is applying what they have researched to solve a problem, produce a product, etc. • Ex. – Testing the effectiveness of certain drugs on the H1N1 virus.

  4. Chemical Technology • Technology is the means by which a society provides its members with those things needed and desired. • Allows humans to do some things more quickly or with less effort. • It allows people to do things that would otherwise be impossible.

  5. Chemical Elements • The simplest form in which a substance exists. Cannot be broken down by a chemical reaction. • 91 occur naturally, the rest are man made. • Colors on the periodic table are determined by state at room temperature. • Each is represented by a one or two-letter symbol. First letter is capitalized, second is lower case.

  6. Some Elements are named after a property • Au: Latin aurum – shining dawn • Br: Greek bromos – stench • H: hydros genes – water born (water former)

  7. Some are named after the location of discovery • Indium (In) • Francium (Fr) • Germanium (Ge) • Californium (Cf) • Helium (He)

  8. Others are also named for a celestial body • Tellurium (Te) • Mercury (Hg) • Uranium (U)

  9. Still others were named after famous scientists. • Nobelium (No) • Curium (Cm) • Einsteinium (Es)

  10. Names for the elements have their origins in several languages: Latin, Greek, OldeEnglish, even Arabic Most of the symbols we use come from the English or Latin names. Some examples of symbols derived from the Latin include: Au - gold Ag - silver Cu - copper Pb - lead

  11. There is one symbol, however, that does not come from English or Latin. W - tungsten The W is from wolfram, the German word for tungsten. The metal is found in the mineral known as wolframite.

  12. The Scientific Method • A process of studying natural phenomena that involves making observations, forming laws and theories, and testing theories by experimentation • Effective problem solving involves developing and implementing a plan. • Science is a dynamic and self-correcting and it involves a certain process, or method.

  13. Science as a Process Observation direct indirect Hypothesis (Testable explanation for a set of observations) Experiment (Controlled as much as possible – variables: independent - manipulated, dependent – responding) (Example – reaction time (dependent) vs. temperature (independent))

  14. Science as a Process No Yes verification Theory New hypothesis (Well-tested explanation for a broad set of observations) Law (Summarizes the results of many observations) Relate While science involves a process, it is also very often influenced by serendipity.

  15. The Difference Between a Theory and a Law • Laws predict what will happen • Theories explainwhy something happens • Which will also allow you to predict what will happen!

  16. Matter • Something that has mass and takes up space (volume) • 4 different states of matter: • Solid – definite shape and volume • Liquid – definite volume, indefinite shape • Gas – indefinite shape and volume • Gas & vapor are NOT the same thing • Vapor describes the gaseous state of a substance that is usually a liquid or solid at room temp • Plasma – very hot, electrons stripped away • The 5th state of matter - ????

  17. Classifying Matter Matter Pure Substance Mixture Element Compound Heterogeneous Homogeneous (solution) Phase –term used to describe any part of a sample with a uniform composition and properties.

  18. Properties of Matter • Properties used to describe matter can be classified as extensive or intensive. • Intensive Properties – depends on the type of matter present, not the amount • density, malleability, conductivity, ductility, luster, mp, bp, color, temp • Extensive Properties – depends on the amount of matter in a sample • mass, length, volume, shape, size • Most properties are INTENSIVE

  19. What to Study?

  20. Physical Properties/Changes • Physical Property – quality or condition of a substance that can be observed or measured without changing the composition of that substance • odor, color, density, solubility, mp, bp • metals – conductivity, malleability, ductility, luster

  21. Physical Change • Physical Change – some properties of the substance change, but the composition does not change • boil, freeze, melt, condense, break, split, cut, grind

  22. Chemical Properties/Changes • Chemical Property – the ability of a substance to undergo a change in composition • rust, burn, rot, decompose, ferment, explode, corrode • Chemical Change – the composition of matter always changes • Deciding between a physical & chemical change, ask yourself if you can get back what you started with. • Answer YES – physical change • Answer NO – chemical change

  23. Chemical Reactions • One or more substances turn into one or more new substances. • Mass is always conserved – Law of Conservation of Mass • Reactant – substance present at the beginning • Product – substance present at the end • Evidence of a chemical change: • Evolution of a gas • Formation of a precipitate (ppt) • Color change • Evolution of heat/transfer of energy • Odor produced

  24. Practice • Identify the following as element, heterogenous mixture, or homogeneous mixture: • Rubbing alcohol • Ice water • Penny • Paint • Paper • Ink • Brass • Al foil • Salsa

  25. Practice • Decide if the following are a chemical or physical change: • Color fades • Digest lunch • Cutting paper • Plant grows • Cloud formation • Turn on flashlight • Ice melts • Wound heals • Fry an egg

  26. Practice • Classify as intensive or extensive property: • Conductivity • Volume • Density • Color • Temperature • Heat content

  27. Phys/Chem Properties Lab REMINDERS!!! Get PART A (observations/properties) done as soon as possible. Don’t put magnet directly on chemical! Once done with Part A, go immediately to steps 7 & 8. Remember whatever water you add you have to evaporate off, so don’t go overboard. Give Fe and S mixture from step 6 to me after you complete your observations. We will do step 11 as a class demo, DO NOT burn the sugar in a test tube. 6 M HCl is located in the beaker on the demo table. BE CAREFUL with this acid, it is strong!!! Disposal  anything in water – down the sink anything else – in the trash

More Related