6th and 8th Science Metric Measurement

International System of Units Abbreviated SI Uses 10 as base unit SI Prefixes kilo hecto deca unit deci centi milli 1000 100 10 1 0.1 0.01 0.001 Larger----------------------------------- smaller (Unit – meter, liter, or gram)

Prefix staircase Kilo hecto deca unit meter deci liter centi gram milli

Length SI standard unit is meter (m) Measure with metric ruler or meter stick Know: 1 meter = 100 cm 1 cm = 10 mm 1 km = 1000 meters If measure desk use what? Why?

Mass Measure of amount of matter in object Depends on number & kind of atoms in object. Standard unit is gram. Use balance to measure mass. (add weight from three slides) Mass stays the same no matter where it is measured.

Weight Measure of gravitational force: attraction between objects 2 factors affect weight: 1) mass of objects 2) distance between objects Standard SI unit is Newton. Use spring scale to measure weight. Changes from place to place if gravity is different

Temperature Measure of how hot or cold SI unit is Kelvin absolute zero = 0 K Most scientists use Celsius 0 C = freezing point of water 100 C = boiling point of water Celsius + 273 = Kelvin Do thermometer section on homework o o o o

Volume Measure of how much space an object occupies Volume of regular solid volume of rectangle= length x width x height V = 2m x 4m x 3m V = 24 m 3 6th Grade - Do the Math page 10 - now You Try It! (page 11)

Volume of a Liquid Measured with graduated cylinder Unit is liter (L) or milliliter (mL) 1 mL = 1 cm Jar of rocks & cotton balls Which has a greater volume? same What is different? mass & weight 3

Volume of an irregular object (like a rock) Use water displacement 1) Fill graduated cylinder so object will be covered ( 30 to 50 mL) 2) Gently drop object into cylinder. 3) Read new volume 4) Subtract (new volume – old volume) *Object must have density greater than 1 (density of water). If density is less than 1, the object will float. Density? What’s that…….?!?!?

Density Mass Measure of amount of matter that occupies a particular space. Formula: Density = mass/volume Problem 1: The mass of a cubic piece of metal is 80 g & its sides measure 2 cm. What is its density? mass = 80g Volume= 2cm x 2cm x 2cm = 8 cm density = 80g = 10 g/cm 8 cm Density Volume 3 3 3

6th grade - Formula: Density = mass/volume Problem 2: Pumice is an igneous volcanic rock, formed by the rapid cooling of lava. What is the density of a 49.8g piece of pumice that has a volume of 83cm ? Identify What do you know? What do you want to find? Plan Write the formula Substitute the given values into the formula Solve Divide Check that your units agree now You Try It! (page 14) 3

6th grade - Problem 3 (p. 15) – A basalt rock displaces 16 mL of water. The density of the rock is 3.0 g/cm . What is the mass of the rock? Identify What do you know? What do you want to find? Plan Write the formula Substitute the given values into the formula Solve Divide Check that your units agree now You Try It! (page 15) 3

8th Grade - Problem 2: The mass of a container and pop is 700g. The container by itself has a mass of 100g. The volume of pop is 200mL. What is its density? mass of pop = 700g – 100g = 600g volume = 200mL Density = 600g = 3g/mL 200mL Demo liquid density

8th grade - Problem 3 – A basalt rock displaces 16 mL of water. The density of the rock is 3.0 g/cm . What is the mass of the rock?

Density Column A substance that is less dense will float on a substance that is more dense. What is the color of the least dense liquid? The density of water = 1