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Science AHSGE Standard I-1, part 2- Appropriate Laboratory Materials.

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Biology AHSGE Standard I- Appropriate Laboratory Materials.

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Presentation on theme: "Science AHSGE Standard I-1, part 2- Appropriate Laboratory Materials."— Presentation transcript:

1 Science AHSGE Standard I-1, part 2- Appropriate Laboratory Materials

2 Measurement Universal system of measurement Systeme International (SI) or Metric System Based on units of ten King Hendry Died By Drinking Chocolate Milk Kilo- 1000s (k) Hecto- 100s (h) Deka- 10s (Da, Dk) Base Deci- 10ths (d) Centi- 100ths (c) Milli- 1000ths (m) Base units Volume, space- liters,cm 3 Mass/weight- Grams Distance, height, width, length- Meters

3 Measurement Accuracy refers to the agreement between a measurement and the true or correct value. Precision refers to the repeatability of measurement. Error refers to the disagreement between a measurement and the true or accepted value.

4 Glassware 1. Do not use glassware that is broken, chipped or cracked. 2. Always use tongs or a heat-resistant glove to heat glassware. a. Point test tube away from yourself and others when heating. b. Allow to cool before storing. 3. If a glassware breaks, do not touch with bare hands. Place in special broken glass container.

5 Glassware Graduated cylinder- piece of laboratory glassware used to accurately measure out volumes of chemicals for use in reactions. Generally more accurate and precise for this purpose than flasks. Read from bottom of meniscus Fluid displacement- Determine the volume of an irregular solid by placing in a graduated cylinder with a known amount of fluid and measuring the difference

6 Glassware Beaker- Simple container for liquids, very commonly used in laboratories. Generally cylindrical in shape, with a flat bottom Do not use to measure volume of a liquid. Use for holding and pouring liquids.

7 Glassware Burette (also buret )- Vertical cylindrical piece of laboratory glassware with a volumetric graduation on its full length and a precision tap, or stopcock, on the bottom. Used to dispense known amounts of a liquid reagent in experiments for which such precision is necessary, such as a titration of an acid experiment. Burettes are extremely precise: class A burettes are accurate to ±0.05 mL.

8 Glassware Fl ask- Wider vessel "body" and one (or sometimes more) narrower tubular sections at the top called necks which have an opening at the top. Flasks can be used for making solutions or for holding, containing, collecting, or sometimes volumetrically measuring chemicals, samples, solutions, etc. for chemical reactions Other processes such as mixing, heating, cooling, dissolving, precipitation, boiling (as in distillation), or analysis.

9 Glassware Pipette (also called a pipet, pipettor or chemical dropper )- Instrument used to transport a measured volume of liquid. Works by creating a vacuum above the liquid-holding chamber and selectively releasing this vacuum to draw up and dispense liquid. May have a bulb for suction.

10 Glassware Petri dish- Shallow glass or plastic cylindrical dish that biologists use to culture cells, which can be bacteria, animal, plant, or fungus Agar is a gelatinous substance chiefly used as a culture medium for microbiological work

11 Glassware Test tube (culture tube )- Piece of laboratory glassware composed of a finger-like length of glass tubing, open at the top, with a rounded U- shaped bottom. Typically used by chemists to retain multiple discrete samples of materials, usually liquids, during chemical procedures and experiments Designed to allow easy heating of these samples.

12 Glassware Microscope slide- thin sheet of glass used to hold objects for examination under a microscope. Wet mount - Object to be viewed is prepared, or mounted, in water underneath a cover slip

13 Mass Measurement Balance (also balance scale, beam balance or laboratory balance) is used to measure the mass of an object. Triple-beam balance – Balance with a pan and three beams with sliding masses called riders At one end is a pointer Indicates whether the mass on the pan is equal to the mass on the beams

14 Mass Measurement Spring scales typically measure force due to gravity, which can be measured in units of force such as newtons or pounds-force.

15 Mass Measurement Analytical balance- instrument used to measure mass to a very high degree of precision. The weighing pan(s) of a high accuracy (0.1 mg or better) Inside a see-through enclosure with doors so dust does not collect and so any air currents in the room do not affect the delicate balance.

16 Time Measurement Stop Watch- does what its name implies enables hand timing has millisecond accuracy and no artificial limit on hours

17 Distance Measurement Distance is the measurement from one point to another. How far away something is Can be length, width, height, depth, altitude, etc. Sometimes need to measure before the volume of a regular solid can be determined: V= L x W x H

18 Distance Measurement Ruler- the instrument used to rule lines and the calibrated instrument used for determining measurement

19 Distance Measurement A tape measure or measuring tape is a ribbon of cloth, plastic, or metal with linear-measure markings, often in both imperial and metric units. A meter stick measures up to 40 inches (3.281 feet) A yard stick measures up to 36 inches (3 feet)

20 Optical Instruments A microscope -instrument for viewing objects that are too small to be seen by the naked or unaided eye. optical instrument containing one or more lenses that produce an enlarged image of an object placed in the focal plane of the lens(es).

21 Optical Instrument Simple Microscope - Microscope with only one lens Compound Light microscope - Microscope with more than one lens which uses light to transmit image to your eye

22 Optical Instrument Electron microscope - uses electrons to illuminate and create an image of a specimen Transmission electron microscopy (TEM) involves a high voltage electron beam emitted by a cathode, usually a tungsten filament, and focused by electrostatic and electromagnetic lenses Scanning Electron Microscope (SEM) produces images by detecting low energy secondary electrons which are emitted from the surface of the specimen due to excitation by the primary electron beam

23 Optical Instrument Reflection Electron Microscope (REM) involves electron beams incident on a surface, but instead of using the transmission (TEM) or secondary electrons (SEM), the reflected beam is detected

24 Optical Instrument Telescope - an instrument designed for the observation of remote objects and the collection of electromagnetic radiation

25 Optical Instrument Magnifying glass - (Hand lens) a convex lens which is used to produce a magnified image of an object

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