3-1 Notes – Density Chapter 3 Lesson 1

Density Which would have more mass? It depends on BOTH the size of the object AND the material contained inside.

Density Density is the amount of mass per unit volume of a material. D = m V

Density Matter is made of atoms which are particles that have mass.

Density Density depends on mass AND the number of particles packed into a given volume.

Density

Density The volume of air has fewer particles, thus less mass than the same volume of water. Thus, the density of air is less than the density of water. <

Density D = m V D – density, the unit is g / cm3 (solids) or g / mL (liquids) m – mass, the unit is g V – volume, the unit is cm3 (solids) or mL (liquids)

Density Density depends on the material an object is made from, NOT its size.

Density Density depends on the material an object is made from, NOT its size.

Density An entire chocolate bar will have the same density as just one piece. It’s all made from the same material – chocolate.

Density Density depends on the mass of the particles. (more mass = more density)

Density Density depends on the distance between particles. (more distance = less density)

Density Gases are usually less dense than solids or liquids because particles are far apart.

Density

Density

Density

Density To make something less dense, you can decrease the mass or increase the volume of an object.

Density A solid steel ball sinks in water, but that same mass of steel made into a curved hull of a boat will float – the shape of the hull causes it to displace a greater volume of water than a solid ball.

Density

Density It was the cold temperature that made the iron more brittle when it struck the iceberg. The water that leaked in canceled out the less dense air inside the boat’s hull. The density of iron guaranteed that it would sink.

Measuring Density Measure its mass. Measure its volume. Divide its mass by its volume.

Measuring Mass For a solid, place it directly on the balance.

Measuring Mass For a liquid: Measure the empty container. Measure the container AND liquid. Subtract the container from the total mass.

Measuring Volume For a liquid, use a graduated cylinder.

Measuring Volume For a regular solid (all sides are rectangles): Measure its length, width, height. Multiply all 3 numbers together.

Measuring Volume For an irregular solid, you have to use the “displacement” method.

Measuring Volume Record the volume of water in a graduated cylinder.

Measuring Volume Place the object CAREFULLY (without splashing) into the graduated cylinder, and record the new volume.

Measuring Volume Subtract the volume of the water from the combined volume. Then you know the volume of just the object.

Measuring Volume What is the volume of the hammer? Initial volume = Final volume = 65 mL 69 mL 69mL - 65 mL 4 mL

Density is a Physical Property A physical property is something you can measure without changing the composition of the material. When you measure an object’s mass and volume, you don’t change it into something else.

Density equals ____ divided by volume. A force B matter C solid D mass

Density ____ as the distance between particles in an object ____. A increases; decreases B increases; increases C decreases; decreases D none of the above

3.1 Density Calculate the volume of a rock that has a mass of 12 g and a density of 3 g/cm3. A 9 cm3 B 15 cm3 C 4 cm3 D 4 cm

Gold has a density of 19. 3 g/cm3. What is the volume of 19 Gold has a density of 19.3 g/cm3. What is the volume of 19.3 g of gold? A 19.3 cm3 B 5 g/cm3 C 15 g/cm3 D 1 cm3

Density is mass per unit ____. A force B matter C pressure D volume SCI 8.a Density is mass per unit ____. A force B matter C pressure D volume

SCI 8.b A 15g object is placed in a graduated cylinder of water. The water level is at 24 ml. When the object is removed, the water level is at 19 ml. What is the density of the object? A 5 g/cm3 B 4 g/cm3 C 3 g/cm3 D 19 g/cm3