Starter quiz 1. Write the general equation for Metal + water Metal + acid Metal + oxygen 2. What metal do you usually put on iron in galvanization? 3. Which metal is higher up in the reactivity series, calcium or copper? Chocolate cake is made up of matter. You are made of matter. Properties describe matter. A block of wood, milk, and air all have properties.

Density Which one is heavier, 3Kg of feathers or 3Kg of rice? Chocolate cake is made up of matter. You are made of matter. Properties describe matter. A block of wood, milk, and air all have properties.

Density The answer is neither, they both have the same mass, the only difference would perhaps be that a bag of feathers look a lot larger than a bag of rice. The rice is more compact and packs its mass into a smaller volume than the feathers, and we say that the rice is more dense than the feathers. Give me examples of something that’s denser than something else.

Density Density is how much mass is packed into a measured volume (how ‘compact’ something is). The formula for density is: mass is grams (g) volume is cubic centimeters (cm-3) density is grams per cubic centimeters (g cm-3) Water has a density of 1 g cm-3 and those things that have a higher density than water will sink whereas those with lower densities will float.

Density Why sugar can make a difference.

Density Experiment: Aim: Measure the density of objects Material: Measuring cylinder, small objects, scale, a piece of splint. Draw up a table with headings like this Object Mass (g) Initial volume of water (V1, mL) Final volume of water (V2, mL) Volume of object (V2-V1) Density (g mL-1)

Density Experiment (and demo) In groups of three, each group should have a measuring cylinder and some small objects to measure the density of, and there are a few scales to share. We need to measure the mass of an object. Use the measuring cylinder to measure the volume of the object. (read the initial volume and after putting the object in (if it floats then push it down so it just sits below the surface) Calculate the density. Question: Which object is more dense?

One thing you have learned today

Density questions: 1. In each of the following questions find the density. State the units of your answer. a Mass 45g, volume 5cm3 d Mass 18.9g, volume 9cm3 2. In each of the following questions find the mass. State the units of your answer. a Density 5g/cm3. volume 4cm3 d Density 190kg/m3, volume 3m3 3. In each of the following questions find the volume. State the units of your answer. a Density 1.4g/cm3. mass 5.6g d Density 800kg/m3, mass 4800kg 4. Lead has a density of 11.5g/cm3. A rectangular block of lead measures 7cm ×5cm×2cm. a) Find the volume of the block of lead. b) Find the mass of the block of lead 5. A plywood plank measures 1cm ×8cm×90cm and weighs 396g. a) Find the volume of the plywood plank. b) Find the density of the plywood.