Worksheet: The Earth and Its Atmosphere | IGCSE Cambridge Science for Year 6 - Class 6 PDF Download

Multiple Choice Questions (MCQ)

Q1. What is the primary composition of Earth's inner core?

A) Silicon and magnesium

B) Iron and nickel

C) Aluminum and silicon

D) Calcium and iron

Answer: B) Iron and nickel

Explanation: The Earth's inner core is primarily composed of iron and nickel, making it extremely dense.

Q2. Which of the following evidence supports the theory of continental drift?

A) Different rock types on each continent

B) Identical fossils found on widely separated continents

C) The presence of unique species on every continent

D) Isolated earthquakes in coastal regions

Answer: B) Identical fossils found on widely separated continents

Explanation: Identical fossils found on different continents suggest these landmasses were once joined, supporting the theory of continental drift.

Q3. What occurs at divergent plate boundaries?

A) Plates move towards each other

B) Plates move apart

C) Plates slide past each other

D) Plates remain stationary

Answer: B) Plates move apart

Explanation: At divergent boundaries, tectonic plates move apart, allowing magma from the mantle to rise and form new crust.

Q4. Which process in the water cycle involves the transformation of water vapor back into liquid form?

A) Evaporation

B) Condensation

C) Precipitation

D) Collection

Answer: B) Condensation

Explanation: Condensation is the process where water vapor cools and turns back into liquid form, forming clouds.

Q5. What geological feature is primarily formed at convergent boundaries?

A) Volcanoes

B) Mountains

C) Rift valleys

D) Mid-ocean ridges

Answer: B) Mountains

Explanation: Mountains are often formed at convergent boundaries through the collision and uplifting of tectonic plates.

Fill in the Blanks

Q1. The Earth's crust varies in thickness from __ to __ km beneath the oceans.

Answer: 5, 10

Explanation: The Earth's crust is thinner beneath the oceans, typically ranging from 5 to 10 km.

Q2. Alfred Wegener proposed the hypothesis of __ drift in 1912.

Answer: continental

Explanation: Alfred Wegener introduced the hypothesis of continental drift, suggesting continents moved apart over time.

Q3. __ currents in the mantle drive the movement of tectonic plates.

Answer: Convection

Explanation: Heat-driven convection currents in the mantle facilitate the movement of the Earth's tectonic plates.

Q4. The release of __ due to the movement of plates causes earthquakes.

Answer: energy

Explanation: Earthquakes are caused by the sudden release of energy due to the movement of tectonic plates, particularly at transform boundaries.

Q5. Industrial activities have increased levels of __, methane, and other pollutants in the atmosphere.

Answer: carbon dioxide

Explanation: Human industrial activities have significantly raised the levels of carbon dioxide and other greenhouse gases in the atmosphere.

True/False

Q1. The Earth's core consists entirely of liquid iron.

Ans:  (False)

Explanation: The Earth's core has a solid inner part made of iron and nickel and a liquid outer part.

Q2. The theory of plate tectonics was widely accepted immediately after being proposed. 

Ans: (False)

Explanation: The theory of plate tectonics faced significant skepticism initially and was accepted only after considerable evidence supported it.

Q3. Volcanoes occur only at convergent boundaries. 

Ans: (False)

Explanation: Volcanoes can occur at both divergent and convergent boundaries.

Q4. Water vapor increases in the atmosphere as temperatures rise. 

Ans: (True)

Explanation: Higher temperatures lead to increased evaporation, raising the amount of water vapor in the atmosphere.

Q5. Fossil evidence played no role in the development of the theory of continental drift. 

Ans: (False)

Explanation: Fossil evidence of identical species on different continents was crucial in supporting the theory of continental drift.

Matching Columns

1-> D) 2-> C) 3-> B) 4->E) 5->1)

1. Subduction - Process where one plate goes under another
2. Mantle - Layer below the crust
3. Wegener - Hypothesis of continental drift
4. Precipitation - Returns water from the atmosphere to the Earth's surface
5. Carbon Dioxide - A greenhouse gas increased by human activities