DCI 1.2 - Density

DCI Clicker Questions

1. Predict what will happen when the solid is dropped into the liquid.a) the solid will sink in the liquidb) the solid will float on the liquid

2. After viewing video describe what you observe happening?a) the solid sank in the liquidb) the solid floats on the liquid

This is an example of adding a solid alcohol to its liquid.

3. Which of the following student statements is the best atomic/molecular level explanation for what you observed happening in the video?

A) The liquid has the lowest density because the molecules are not as closely compacted and are free to move around.B) The liquid has the lowest density because there is more empty space (or air-filled space) between molecules than in the solid. The open space decreases the density because it is lighter than the molecules.C) The liquid has a lower density. Density = mass/volume and the solid has a greater mass because it has more particles per unit volume. Hence, the density of the solid would be greater than the liquid.D) The atoms and molecules in the solid phase are clearly more dense.E) Solid molecules weigh less than liquid molecules for a pure substance.F) Liquid molecules weigh less than solid molecules for a pure substanceG) The liquid would have a lower density since its shape but not volume can be changed.

1. Predict what will happen when the solid is dropped into the liquid.a) the solid will sink in the liquidb) the solid will float on the liquid

2. After viewing video describe what you observe happening?a) the solid sank in the liquidb) the solid floats on the liquid

This is an example of adding

solid water to its liquid.

3. Which of the following student statements is the best atomic/molecular level explanation for what you observed happening in the video?

A) The solid has the lowest density because the molecules are not as closely compacted and are free to move around.B) The solid has the lowest density because there is more empty space (or air-filled space) between molecules than in the liquid. The open space decreases the density because it is lighter than the molecules.C) The solid has a lower density. Density = mass/volume and the liquid has a greater mass because it has more particles per unit volume. Hence, the density of the liquid would be greater than the solid.D) The atoms and molecules in the liquid phase are clearly more dense.E) Liquid molecules weigh less than solid molecules for a pure substance.F) Solid molecules weigh less than liquid molecules for a pure substanceG) The solid would have a lower density since its shape but not volume can be changed.

4. Below are two images representing water at the level of atoms and molecules (the particulate level).

a) Identify the phase (gas, liquid or solid) depicted in Figure I.1) Gas2) Liquid3) Solid

b) Identify the phase depicted in Figure II.1) Gas2) Liquid3) Solid

Figure I Figure II

The three colored balloon of equal volume each contain a different gas. The three possible gases are helium, air, and argon.

1. The green balloon containsa) heliumb) airc) argon

2. The blue balloon containsa) Heliumb) Airc) argon

3. The red balloon containsa) Heliumb) Airc) argon