1. Making Metric Measurements

2. Ruler Metric rulers are fairly easy to read. They deal with centimeters and millimeters only. You won’t have to worry about fractions. Take a look at the following Metric Ruler: The large lines with numbers are centimeters and the small lines are millimeters. When we measure something, we always estimate between the smallest marks. Scientists always understand that the last number measured is actually an estimate.

3. Ruler Reading a Metric Ruler: 1. The beauty of the metric system is that it is based on the number 10. The diagram above shows you a section of a metric ruler. Each numbered line represents one centimeter (cm). 2. Each small mark after the numbered lines represents one tenth of a centimeter or one millimeter (mm). 1 cm = 10 mm (there are 10 mm in 1 cm) 55 cm = 550 mm (multiply by 10)

4. Ruler 3. There are lettered arrows over the diagram of the ruler above. If an object ended at "C", it would be 2.20 cm long. In the metric system, we always use decimals, never fractions. You must always include a unit like centimeter in your answers. You may use abbreviations. 4. If the measurement ends in between the line you must estimate a number (between 1-9).

5. A – B – C – D – E – F – G –

6. A – 0.59 cm B – 1.20 cm C – 2.19 cm D – 3.70 cm E – 5.60 cm F – 6.70 cm G – 7.51 cm

7. Liquids in Graduated Cylinders You should be able to measure the volume of liquids in a graduated cylinder. How precisely you can measure volume depends on the size and type of graduated cylinder you use. Generally, you should be able to estimate between the etched or printed lines.

8. Liquids in Graduated Cylinders It is important to notice what each line or interval on the graduated cylinder represents. Different kinds of graduated cylinders are set up differently. The way to check this is to count the divisions between consecutive numbers.

9. Liquids in Graduated Cylinders It is important to notice what each line or interval on the graduated cylinder represents. Different kinds of graduated cylinders are set up differently. The way to check this is to count the divisions between consecutive numbers. top # - bottom #/# divisions 100 – 80/20 = 1 mL

10. Liquids in Graduated Cylinders On some cylinders, there may only be five divisions between numbers. Or there may be ten divisions for a 2 milliliter increment. In these cases, each of the divisions represents 0.2 milliliters, rather than 0.1. You need to be aware, when you're using the cylinders like these, and adjust your between-line- estimates accordingly..2 mL increments1 mL increments

11. Liquids in Graduated Cylinders The Meniscus A characteristic of liquids in glass containers is that they curve at the edges. This curvature is called the meniscus. You measure the level at the horizontal center or inside part of the meniscus. With water in glass, the meniscus will curve up at the edges and down in the center so we say you read the bottom of the meniscus.

12. Liquids in Graduated Cylinders The Meniscus There are some materials where the curve goes the other way. Still, you read the horizontal center of the meniscus. In this case it would be the top of the meniscus. In some plastic cylinders water has a flat surface. In that case, top or bottom doesn't matter, but we can still say use the center rather than the edges.

13. Liquids in Graduated Cylinders The Meniscus The visibility of the meniscus can be enhanced by using a card with a dark stripe on it, placed behind the cylinder. Adjusting the placement of the card can give you either a white meniscus against a black background or a black meniscus against a white background.

16. 12.0 mL16.0 mL 14.0 mL

18. Water Displacement

19. _______ mL Volume of dinosaur toy = cm³ and cc are also units used for volume – 1 mL = 1 cm³ = 1 cc

20. 4.80 mL5.60 mL Volume of dinosaur toy = 5.60 – 4.80 = 0.8 mL cm³ and cc are also units used for volume – 1 mL = 1 cm³ = 1 cc

21. Triple Beam Balance The triple beam balance is used to measure mass. With the pan empty, move the three sliders on the three beams to their leftmost positions, so that the balance reads zero. If the indicator on the far right is not aligned with the fixed mark, then calibrate the balance by carefully turning the set screw on the left under the pan. Once the balance has been calibrated, place the object to be measured on the pan. Move the 100 gram slider along the beam to the right until the indicator drops below the fixed mark. The notched position immediately to the left of this point indicates the number of hundreds of grams.

22. Triple Beam Balance Now move the 10 gram slider along the beam to the right until the indicator drops below the fixed mark. The notched position immediately to the left of this point indicates the number of tens of grams. The beam in front is not notched; the slider can move anywhere along the beam. The boldface numbers on this beam are grams and the tick marks between the boldface numbers indicate tenths of grams. To find the mass of the object on the pan, simply add the numbers from the three beams. As with a ruler, it is possible to read the front scale to the nearest half tick mark.

23. Triple Beam Balance Read the Balance

24. Triple Beam Balance Read the Balance

25. Triple Beam Balance Read the Balance

26. Triple Beam Balance Read the Balance 100 + 10 + 6.77 = 116.77 grams (116.77 g)

27. Triple Beam Balance Read the Balance 100 + 60 + 3.70 = 163.70 g

28. Triple Beam Balance Read the Balance 300 + 30 + 8.20 = 338.20 g

29. Thermometers Laboratory thermometers are not to be shaken. Do not use a thermometer as a stirring rod for stirring solutions. Make sure the thermometer is not located near the edge of the lab table. There are three temperature scales, Fahrenheit, Celsius, and Kelvin We will measure in degrees Celsius (ºC)

30. Thermometers The liquid being measured should be well mixed to ensure a uniform temperature. The entire bulb of the thermometer should be in the liquid. The thermometer should remain long enough in the liquid to ensure that it comes to thermal equilibrium at the temperature which is being measured. When temperature changes are being measured, one can reduce the error by taking both temperatures with the same thermometer.

31. Thermometers Measuring with a Thermometer: When you use a thermometer there may be graduations every 1 °C or 0.5 °C. Check the divisions on your thermometer. Always read the thermometer starting at the zero mark. If the reading is greater than zero read up the thermometer. If the reading is less than zero read down the thermometer.