Earth's rotation causes day and night, as shown in this image of the planet's illuminated side.

Let's go through each question on the worksheet "Earth's Rotation and Revolution" and solve them one by one, explaining the reasoning behind each answer.

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1. The words rotate and revolve have the same meaning when describing the motion of planets.

- a. True
- b. False

✔ Correct Answer: b. False

Explanation:
- Rotate means to spin around its own axis (like Earth spinning on its axis every 24 hours).
- Revolve means to orbit around another object (like Earth going around the Sun).
- These are different motions, so they do not mean the same thing.

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2. The movement of Earth around the Sun once every 365.25 days is called _________.

- a. rotation
- b. revolution

✔ Correct Answer: b. revolution

Explanation:
- Revolution refers to the Earth’s orbit around the Sun.
- It takes about 365.25 days for one complete revolution — that’s why we have leap years every 4 years.

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3. The movement of Earth as it takes 24 hours to spin on its axis is called _________.

- a. rotation
- b. revolution

✔ Correct Answer: a. rotation

Explanation:
- Rotation is the spinning of Earth on its axis.
- This rotation takes approximately 24 hours, which defines one day.

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4. What is the shape of a planet's orbit?

- a. circular
- b. irregular
- c. elliptical

✔ Correct Answer: c. elliptical

Explanation:
- Planets orbit the Sun in elliptical (oval-shaped) paths, not perfect circles.
- This was discovered by Johannes Kepler and is part of his laws of planetary motion.

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5. The picture shows the daylight side of Earth. Which best describes why Earth has day and night?

*(Image of Earth with sunlight on one side)*
- a. The Moon rotates on an axis.
- b. Earth rotates on an axis.
- c. The Moon revolves around Earth.
- d. Earth revolves around the Sun.

✔ Correct Answer: b. Earth rotates on an axis.

Explanation:
- As Earth rotates on its axis, different parts face the Sun (day) or turn away from it (night).
- This daily cycle of day and night is due to rotation, not revolution.

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6. One complete revolution of Earth around the Sun is called a

- a. day
- b. night
- c. month
- d. year

✔ Correct Answer: d. year

Explanation:
- A year is defined as the time it takes Earth to complete one full orbit (revolution) around the Sun — about 365.25 days.

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7. What causes the apparent movement of the Sun across the sky during the day on Earth?

- a. revolution of Earth in its orbit
- b. rotation of Earth on its axis
- c. location of Earth in space
- d. objects are moving around Earth

✔ Correct Answer: b. rotation of Earth on its axis

Explanation:
- The Sun appears to move across the sky because Earth is rotating.
- As Earth spins from west to east, the Sun seems to rise in the east and set in the west.
- This is an apparent motion caused by Earth’s rotation, not actual movement of the Sun.

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8. How long does it take for Earth to rotate once on its axis?

- a. 1 day
- b. 1 year
- c. 1 week
- d. 1 month

✔ Correct Answer: a. 1 day

Explanation:
- One full rotation of Earth on its axis takes approximately 24 hours, which is defined as one day.

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✔ Final Answers Summary:

| Question | Answer |
|--------|--------|
| 1 | b. False |
| 2 | b. revolution |
| 3 | a. rotation |
| 4 | c. elliptical |
| 5 | b. Earth rotates on an axis |
| 6 | d. year |
| 7 | b. rotation of Earth on its axis |
| 8 | a. 1 day |

This worksheet helps students understand the difference between rotation (spinning on axis) and revolution (orbiting the Sun), and how these motions affect day/night cycles and the calendar year.