EQ: How do we use the metric system in science?

Transcription

1 #2 EQ: How do we use the metric system in science?

2 Introduction to the Metric System In science class, we will be using the International System (SI) for measurements. (SI is French for Systeme Internationale) Metric System 7 What is the International System (SI)? In the United States, we use the English or Standard measurement System. EQ: How do we use the metric system in science? Why do we use it? It s based on multiples of 10 and the metric system of measurement.!easy to learn; easy to understand and remember!most countries only use the metric system!common way for scientists to share and compare their results

3 km m Length/Distance cm mm Length is a measure of how long or how far. The basic unit of length in the metric system in the meter and is represented by a lowercase m. To measure length we use a ruler or a meter stick. Metric Units 1 Kilometer (km) = 1000 meters 1 Meter = 100 Centimeters (cm) 1 Meter = 1000 Millimeters (mm)

4 Prefixes Matter When you add a prefix to a base unit you change it s value.!kilo- (k) = 1000!Centi- (c) =.01 (1/100)!Milli- (m) =.001 (1/1000) How do we make sense of the metric system? 1000 meters = 1 kilometer (km)...a little bit more than 1/2 mile 1/100th of a dollar is a cent not penny")...so 1/100th of a meter must be 1 centimeter (cm)...and so there must be 100 cm in 1 m How many numbered marks are on a meter? 100 Therefore each numbered mark must be a centimeter Each cm is divided into 10 little spaces (tiniest marks)

5 How do we make sense of the metric system? 1000 meters = 1 kilometer (km)...a little bit more than 1/2 mile 1/100th of a dollar is a cent not penny")...so 1/100th of a meter must be 1 centimeter (cm)...and so there must be 100 cm in 1 m How many numbered marks are on a meter? 100 Therefore each numbered mark must be a centimeter Each cm is divided into 10 little spaces (tiniest marks)...so how many little spaces per meter? 1000 (10 x 100) If there are 1000 little spaces in the meter, each space must be 1/1000th of a meter. 1/1000th of something is a milli-something, so each little space must be called a... millimeter (mm)

6 kg g Mass cg mg Mass is the amount of matter in an object. The base unit of mass in the metric system in the gram and is represented by g. To measure mass, we use a triple beam balance. Kilogram Prototype Metric Units 1 Kilogram (kg) = 1000 Grams (g) 1 Gram (g) = 1000 Milligrams (mg) Click the image to watch a short video about mass.

7 kl L Volume cl ml Volume is the amount of space an object takes up. The base unit of volume in the metric system in the liter and is represented by L or l. To measure volume, we use a graduated cylinder. Metric Units 1 liter (L) = 1000 milliliters (ml) 1 milliliter (ml) = 1 cm 3 (or cc) = 1 gram* Click the image to watch a short video about volume.

8 Measuring Length How many millimeters are in 1 centimeter? 1 centimeter = 10 millimeters 2.8 What is the length of the line in centimeters? cm What is the length of the line in millimeters? mm 28 What is the length of the line to the nearest centimeter? cm HINT: Round to the nearest centimeter no decimals. 3

9 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

10 Measuring Volume We will be using graduated cylinders to find the volume of liquids and other objects. 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.

11 Measuring Solid Volume 9 cm We can measure the volume of regular object using the formula length x width x height. 8 cm cm 3 X X = 10 cm We can measure the volume of irregular object using water displacement. Amount of H 2 O with object = Amount of H 2 O without object = Difference = Volume = 260 cm cm 3 60 cm 3

12 Metric Lab Station #1 - MASS -mass any 8 objects in classroom (not from Mrs Wingo s desk) -write number and unit (g) -draw each object & color (min 4 colors total) Station #2 - LENGTH -scavenger hunt: write exact measurement -don t forget to include UNITS (cm or m) Station #3 - Volume -put on apron and googles **caution: careful with glass beakers and test tubes you break it, you buy it!! -follow directions carefully

13 Station #1: Mass Name: Period: Directions: (only pick up balance by base and arm with two hands) Mass 8 objects on triple beam balance. Write item name and mass. (DON T FORGET UNITS) Draw each object and color. (min 4 colors) Station #2: Length Directions: Find an object in the classroom that has a length between: Length Object Name: Period: Measurement (cm or m) 0-1 cm 1-3 cm Item Name: Mass: Item Name: Mass: 5-10 cm cm cm Item Name: Mass: Item Name: Mass: cm cm cm Item Name: Mass: Item Name: Mass: cm cm 50 cm - 2 m Item Name: Mass: Item Name: Mass: cm Your Height Bonus: Your Height in meters: m

14 Station #3: Volume Name: Period: Part A: Volume with a Graduated Cylinder 1. Obtain the following items from your teacher: 3 beakers with colored water-25 ml of each color (red, blue, & yellow) 2 graduated cylinders (10 ml and 25 ml) 1 eyedropper or pipet 6 test tubes labeled A,B,C,D,E, & F 2. Perform each step outlined below using ACCURATE measurements. (1) Measure 17 ml of RED water from the beaker & pour into test tube A. (2) Measure 21 ml of YELLOW water from the beaker & pour into test tube C. (3) Measure 22 ml of BLUE water from the beaker & pour into test tube E. (4) Measure 5 ml of the red water from test tube A & pour it into test tube B. (5) Measure 2 ml of red water from test tube A & pour it into test tube F. (6) Measure 5 ml of yellow water from test tube C & pour it into test tube B. (7) Measure 6 ml of yellow water from test tube C & pour it into test tube D. (8) Measure 8 ml of blue water from test tube E & pour it into test tube F. (9) Measure 4 ml of blue water from test tube E & pour it into test tube D. 3. Before cleaning your test tubes, record the color in each test tube and measure the amount of water using a graduated cylinder. Complete the chart. Test Tube Color Final Amount (ml) Part B: Volume using Water Displacement Follow the directions to find the volume of a marble using water displacement. (1) Add 15 ml of water to a 25 ml graduated cylinder. Record this amount on the chart. (2) Add marble to the cylinder & measure the volume. Record this amount on the chart. (3) Find the difference between the two measurements & record on the chart. The difference between the two measurements will be the volume of the marble. Volume of water before adding marble Volume of water after adding marble Part C: Volume by Formula Use the formula to find the volume of the box. Difference in Volume Volume of marble = A B C D E F 3 cm 3 cm Volume = length x width x height 5 cm 4. Clean up. Carefully carry one test tube in each hand to sink, dump water and rinse. Put test tubes back on rack. x x = cm 3

15 8/20/18 Agenda Time (It s Monday don t miss any participation points) -get out your Moore Agenda and copy the agenda for science for the week ***show Mrs Wingo when done Assignment #3 (pg 11) Task: Create a tree map of the Metric System

16 Name Date Class S K I L L S A S S E S S M E N T Skills Test B: Measuring and Calculating Questions 1 5. Use the diagram below to answer each question. Write your answer on the line at the left. Name Date Class Skills Test B: Measuring and Calculating (continued) Questions 9 10: Make the necessary calculations and give your answer in the space below each question. 9. What is the area of the rectangle on the right? 10. What is the volume of the figure on the right? 1. How many centimeters long is Leaf A? 2. How many centimeters long is Leaf B? 3. How many centimeters longer is Leaf A than Leaf B? 4. How many millimeters long is Leaf A? 5. How many millimeters long is Leaf B? Questions 11 12: Use the information provided below and the diagram on the right to answer the questions. You can show your work below or use the back of this page. Write the answer to each question on the line at the left. (ml) Prentice-Hall, Inc. Questions 6 8: Use the diagrams below to answer each question. Write your answer on the line at the left. (Labeled measurements are in ml.) Suppose you need to measure the volume of a small rock. You decide to use water and a graduated cylinder to find that measurement. You obtain the results shown on the right. 6. What is the volume of the water in graduated cylinder A? 7. What is the volume of the water in graduated cylinder B? 8. What is the volume of the water in graduated cylinder C? 11. What is the volume of the water plus the rock? 12. What is the volume of the rock alone? Inquiry Skills Activity Book Inquiry Skills Activity Book

17 Lab Safety and Metric System Review Across 6. Instrument used to measure length (2 words) 9. Metric measurement for the amount of matter (stuff) in an object 11. Instrument used to measure volume (2 words) 13. Used for holding very small amounts of substances (two words) 15. Basic metric unit for mass 16. Used for transferring a small amount or drops of liquid 17. Used for holding and pouring liquids 18. Metric measurement for the amount of space an object takes up Down 1. Protects the eyes from flying objects or chemical splashes (two words) 2. If there is a spill or accident during the lab, you should tell the 3. Metric measurement for how long or how far 4. If after reading the lab directions you do not understand something, you should the teacher for help 5. Basic metric unit for volume (liquid) 7. 1 meter = To find volume by formula, you multiply length x width x 9. Basic metric unit for length 10. Mrs. Wingo's #1 rule in lab: Act! 12. Metric system is based on multiples of 14. Three ways to find volume include using a graduated cylinder, by formula or water Name Date Class Skills Test B: Measuring and Calculating (continued) Questions 13 14: Use the diagram below to answer each question. Write your answer on the line at the left. 13. What is the mass of the container and the sand together? Name three reasons we use the metric system in science: Sand 14. If the mass of the container is 14.5 grams, what is the mass of the sand? Questions 15 19: The diagram below shows five Celsius thermometers. Use these diagrams to answer each question. Write your answer on the line at the left.