Exploring Density Webquest Project

Students will be able to apply skills of using a triple beam balance, water displacement method for calculating volume and measurement method for calculating volume to calculate the density of objects. After conducting research to find what certain substances densities are students will identify the objects. We study characteristic properties to better understand and be able to classify a substance. Students will see how a particular substance has a specific density and can be identified based on this information.

Introduction

Students will be introduced to the topic of characteristic properties and will begin to understand density as it applies to specific substances. Students will conduct research, conduct a hands-on investigation and draw conclusions based on research and their exploration of substances.

Why does oil float on water? Does it have to do with measurements you can make? The image shows two identical containers sitting on a balance. One contains 50mL of water, the other contains 50mL of heavy water (water with dissolved deuterium in it). Both samples take up the same amount of space. However, the heavy water has more mass, because the balance tips down on its side. Why does this happen?

Heavy water has more mass than plain water does. The amount of mass in a given amount of space is the density of an object.

You can find the density of an object by…

1. Find the mass,

2. Find the volume,

3. Divide the mass by the volume.

D=M/V

When an object is placed in a less dense liquid or gas, the object will sink toward the bottom. If the liquid or gas is more dense, the object will float toward the top. If the object has the same density as the liquid or gas, it will “hover” in place.

A characteristic property is a chemical or physical property that helps identify and classify substances. The characteristic properties of a substance are always the same whether the sample you are observing is large or small.

Characteristic properties of an object…