Lab Equipment Ms. Whittaker

Length Meter Stick Use cm or mm 1 cm =_______mm The base unit is the METER Use cm or mm 1 cm =_______mm 10 Ruler is used to measure items larger than a ruler, otherwise a ruler is okay. 1 cm = 10 mm

Volume Base unit is the LITER We measure volume using… Graduated Cylinder Flask Beaker Use milliliters (ml) or Liters (L) Erlenmeyer flasks and beakers are used for mixing, transporting, and reacting, but not for accurate measurements. That is why we use graduated cylinders, because they are the most specific for measuring small, specific volumes.

Measuring Volume What is the volume of water in the cylinder? _____mL Read the measurement based on the bottom of the meniscus or curve. When using a real cylinder, make sure you are eye-level with the level of the water. What is the volume of water in the cylinder? _____mL 43 What causes the meniscus? A concave meniscus occurs when the molecules of the liquid attract those of the container. The glass attracts the water on the sides. Top Image: http://www.tea.state.tx.us/student.assessment/resources/online/2006/grade8/science/images/20graphicaa.gif Bottom Image: http://morrisonlabs.com/meniscus.htm

Measuring Liquid Volume What is the volume of water in each cylinder? 52 mL 37 mL 23 mL Images created at http://www.standards.dfes.gov.uk/primaryframework/downloads/SWF/measuring_cylinder.swf A B C Pay attention to the scales for each cylinder.

Measuring Solid Volume 10 cm 9 cm 8 cm We can measure the volume of regular object using the formula length x width x height. 10 8 9 720 cm3 _____ X _____ X _____ = _____ http://resources.edb.gov.hk/~s1sci/R_S1Science/sp/en/syllabus/unit14/new/testingmain1.htm We can measure the volume of irregular object using water displacement. Amount of H2O without object = ______ About of H2O with object = ______ Difference = Volume = ______ 200 mL 260 mL 60 cm3 NOTE: 1 mL = 1 cm3

Mass Balance Digital Triple beam Base unit is the GRAM Triple beam  slide masses acorss the beams to find an analog value of mass Digital  has a digital readout that gives the weight in typically 0.1 gram accuracy.  faster

Digital Scale You must ZERO/TARE the scale before measuring mass.

TARE the balance with the container first, then add material to be measured (liquid/granules) You do not want the mass of the container in your reading.

Measuring Mass – Triple-Beam Balance 1st – Place the film canister on the scale. 2nd – Slide the large weight to the right until the arm drops below the line. Move the rider back one groove. Make sure it “locks” into place. 3rd – Repeat this process with the top weight. When the arm moves below the line, back it up one groove. 4th – Slide the small weight on the front beam until the lines match up. 5th – Add the amounts on each beam to find the total mass to the nearest tenth of a gram.

_______ + ______ + _______ = ________ g Measuring Mass We will be using triple-beam balances to find the mass of various objects. The objects are placed on the scale and then you move the weights on the beams until you get the lines on the right-side of the scale to match up. Once you have balanced the scale, you add up the amounts on each beam to find the total mass. What would be the mass of the object measured in the picture? _______ + ______ + _______ = ________ g 70 300 3.4 373.4 Top Image: http://www.southwestscales.com/Ohaus_Triple_Beam_750-SO.jpg Bottom Image: http://www.regentsprep.org/Regents/biology/units/laboratory/graphics/triplebeambalance.jpg

Test Tube/Test Tube Rack Test tubes are used to hold, mix, or heat small quantities of solid or liquid chemicals, especially for qualitative experiments and assays.

Test Tube Brushes

Pipette Used to transport a measured volume of liquid and has an incredibly high accuracy/precision rate

Funnel

Petri Dish a shallow glass or plastic cylindrical lidded dish that biologists use to culture cells

Microscope Slide

Microscope Cover Slip The main function of the cover slip is to keep solid specimens pressed flat, and liquid samples shaped into a flat layer of even thickness. This is necessary because high-resolution microscopes have a very narrow region within which they focus.

Compound Light Microscope