Question

part c – matching (5 questions)
match the object or liquid with the correct description of how it behaves in water.
object/liquid
a. rock
b. oil
c. plastic ball
d. ice cube
e. steel nail
description

1. floats, less dense than water
2. sinks, denser than water
3. slightly less dense than water, floats partly submerged
4. floats on water because density is lower
5. sinks due to high density

Explanation:

• A. Rock: Rocks are generally denser than water, so they sink. Description 2 ("Sinks, denser than water") or 5 ("Sinks due to high density") could apply, but 2 is more direct about density comparison.
• B. Oil: Oil has a lower density than water, so it floats on the surface. Description 1 ("Floats, less dense than water") or 4 ("Floats on water because density is lower") work; 1 is concise about density and floating.
• C. Plastic ball: Most plastic balls are less dense than water and float fully or partly, but often they float (less dense). Description 1 or 4, but 1 is about less dense and floating. Wait, no—plastic balls can vary, but typically if it's a light plastic ball, it floats (less dense). But maybe the intended is 1? Wait, no, let's recheck. Wait, ice cube is slightly less dense (so 3), plastic ball—maybe 1? Wait, no, let's think again.
• D. Ice cube: Ice is slightly less dense than water (about 9% less), so it floats partly submerged. So Description 3 ("Slightly less dense than water, floats partly submerged").
• E. Steel nail: Steel is much denser than water, so it sinks due to high density. Description 5 ("Sinks due to high density") or 2. 5 is more about the reason (high density), 2 is about density comparison. But steel nail's high density causes it to sink, so 5.

Now, let's match properly:

• A (Rock): Denser than water → sinks. So 2 ("Sinks, denser than water") or 5. Let's see the options. 2 is "Sinks, denser than water"; 5 is "Sinks due to high density". Both are correct, but maybe 2 for A? Wait, no—rock is denser, so 2.

• B (Oil): Less dense → floats. 1 ("Floats, less dense than water") or 4. 1 is more direct.

• C (Plastic ball): Less dense than water → floats. So 1? Wait, no, maybe 4? Wait, 4 says "Floats on water because density is lower"—that's also correct. But maybe the intended is:

Wait, let's recall standard density concepts:

• Rock: density > water → sink (2: Sinks, denser than water)
• Oil: density < water → float (1: Floats, less dense than water)
• Plastic ball: density < water → float (4: Floats on water because density is lower) – maybe 4, as 1 is for oil? Wait, maybe the options are:

Wait, the descriptions:

1. Floats, less dense than water

1. Sinks, denser than water

1. Slightly less dense than water, floats partly submerged

1. Floats on water because density is lower

1. Sinks due to high density

So:

• A. Rock: Denser than water → sink. So 2 (sinks, denser) or 5 (sinks due to high density). Let's pick 2 or 5. Let's see, rock's density is higher than water, so 2.

• B. Oil: Less dense → float. 1 (floats, less dense) or 4 (floats because density lower). 1 is more direct.

• C. Plastic ball: Less dense → float. 4 (floats because density lower) – since 1 is for oil? Maybe.

• D. Ice cube: Slightly less dense (so 3: Slightly less dense, floats partly submerged)

• E. Steel nail: High density → sink. 5 (sinks due to high density)

So correct matches:

A - 2

B - 1

C - 4

D - 3

E - 5

Answer:

A. Rock - 2. Sinks, denser than water
B. Oil - 1. Floats, less dense than water
C. Plastic ball - 4. Floats on water because density is lower
D. Ice cube - 3. Slightly less dense than water, floats partly submerged
E. Steel nail - 5. Sinks due to high density