MEASUREMENTS AND LAB EQUIPMENT OBJ 2 AB 3

MEASUREMENTS AND LAB EQUIPMENT (OBJ 2: A-B; 3)

MEASUREMENT • What is a measurement? • A measurement is a quantity that has both a number and a unit. • How are measurements used in science? • To collect data and to keep track of the amounts being used

UNITS (DON’T NEED TO WRITE) • What is a unit? • Units are standard values • Why do we use units? • Units allow people to be able to compare data and to be consistent

TYPES OF MEASUREMENTS • Qualitative measurements deal with observations or “qualities”. • Quantitative measurements deal with numbers or “quantities”.

TYPES OF MEASUREMENTS • Label the following as quantitative or qualitative • A wooden block is 1 foot in lengthquant • A wooden block is red in color qual • The solution is blue • The solution is 321 m. L in volumequan t

MAKING QUANTITATIVE MEASUREMENTS • A quantitative measurement should have both a number and unit. • When making the measurement you write down the known digits plus one that is estimated • In the measurement 12. 49 cm the 12. 4 are known and the 9 is estimated

MEASUREMENT (DON’T NEED TO WRITE) • Every experimental measurement has a degree of uncertainty. • The volume, V, at right is certain in the 10’s place, 10 m. L<V<20 m. L • The 1’s digit is also certain, 17 m. L<V<18 m. L • A best guess is needed for the tenths place. 7

MEASUREMENT (CONT)

MEASUREMENT (CONT) • What is the Length? • We can see the markings between 1. 6 -1. 7 cm • We can’t see the markings between the. 6 -. 7 • We must guess between. 6 &. 7 • We record 1. 67 cm as our measurement • The last digit 7 was an estimate but all three numbers are still part of the measurement

MEASUREMENT (CONT) What is the length of the wooden stick? 1) 4. 5 cm 2) 4. 54 cm 3) 4. 547 cm

LAB EQUIPMENT Match the following to the proper measuring tool 1. 2. 3. 4. Temperature Mass A. Graduated cylinder B. Scale/balance C. Scale/balance and ruler D. Thermometer Density Volume Answer Key: 1 = D, 2 = B, 3 = C, 4 = A

LAB EQUIPMENT Match the following to the proper measuring tool 1. 2. A. Beaker B. Scale/balance C. Hot plate D. Thermometer 3. Answer Key: 1 = D, 2 = A, 3 = B, 4 = C 4.