Chapter 1: Introduction to Matter Section 2: Measuring Matter

Weight Measure of the force of gravity on you. Changes depending on location. e.g. An object weighs less on the moon than it does on Earth because the force of gravity is weaker on the moon than it is on Earth. Physical property

Mass Measurement of the amount of matter in the object. Does not change with location or the force of gravity. Preferred measure of matter over weight. Physical property Tool: triple beam balance Units International System of Units (SI) unit of mass is the kilogram (kg). Also commonly measured in grams (g) 1 kg = 1,000 g 1 g = 0.001 kg

Checkpoint 1 What is the difference between mass and weight?

Checkpoint 1 What is the difference between mass and weight? Weight changes based on the force of gravity; mass is constant.

Volume Amount of space that matter occupies. Units: liter (L), milliliter (mL), and cubic centimeter (cm3) 1 L = 1,000 mL 1 mL = 0.001 L 1 mL = 1 cm3 Finding the volume of liquids: use a graduated cylinder Calculating the volume of regular solids: use a ruler to measure the length, width and height Volume = L x W x H Units = cm x cm x cm = cm3 Calculating the volume of irregular solids: submerge the object in water in a graduated cylinder; the water level will rise by an amount equal to the volume of the object in mL (displacement method) Physical property

Using a Graduated Cylinder Meniscus: concave surface of a liquid resulting from surface tension. Should always measure a liquid in a graduated cylinder from the bottom of the meniscus. Graduated cylinders with smaller gradations are more accurate. In order to report the correct number of significant digits, you should estimate one additional digit beyond the gradation increment.

Volume = 43.0 mL

Volume of water = 4.80 mL Volume of dinosaur = 0.80 mL Volume of water + dinosaur = 5.60 mL

Checkpoint 2 What is the volume of the liquid shown below?

Checkpoint 2 What is the volume of the liquid shown below? 73.0 mL

Density Measurement of how much mass of a substance is contained in a given volume. D = m/v Units: g/mL or g/cm3 Objects with a greater density will sink; objects with a lesser density will rise. Physical property Intrinsic/Intensive property (the same for a given substance regardless of size, shape, or amount; e.g., water always has a density of 1 g/ml) Can be used to identify and classify matter.

Checkpoint 3 The mass of an object is 10 grams and its volume is 5 cm3. What is the object’s density?

Checkpoint 3 The mass of an object is 10 grams and its volume is 5 cm3. What is the object’s density? D = m/v = 10 g/5 cm3 = 2 g/cm3

Post-lesson Quiz 1. Which of the following tools are used to measure mass? a. graduated cylinder b. ruler c. triple beam balance d. thermometer

Post-lesson Quiz 2. Which of the following tools are used to measure the volume of liquids? a. graduated cylinder b. ruler c. triple beam balance d. thermometer

Post-lesson Quiz 3. An object floats in water. How does the object compare to the water? a. it is heavier b. it is lighter c. it is denser d. it is less dense

Post-lesson Quiz 4. Which of the following is a measure of the amount of space that matter occupies? a. mass b. density c. volume d. weight

Post-lesson Quiz 5. What is the volume of the liquid below? a. 36.5 mL b. 35 mL c. 37.0 mL d. 36 mL