Short and Long Questions: Understanding the Earth | Footprints Class 7: Book Solutions, Notes & Worksheets PDF Download

Short Answer Questions

Q1: What is the Earth's crust composed of?
Ans: The Earth's crust is composed of rocks and minerals.

Q2: Define geology.
Ans: Geology is the study of the Earth's structure, composition, and history.

Q3: What are the three layers of the Earth?
Ans: The three layers of the Earth are the crust, mantle, and core.

Q4: Explain the difference between continental crust and oceanic crust.
Ans: Continental crust is thicker, less dense, and made up of mostly granitic rocks. Oceanic crust is thinner, denser, and composed mainly of basaltic rocks.

Q5: What are the main minerals of the lower oceanic crust?
Ans: The main minerals of the lower oceanic crust are olivine, pyroxene, and plagioclase feldspar.

Q6: Describe the mantle of the Earth.
Ans: The mantle is the layer between the crust and the core. It is composed of hot, solid rock that flows very slowly over long periods of time.

Q7: What are rocks and minerals?
Ans: Rocks are made up of minerals. Minerals are naturally occurring, inorganic substances with a specific chemical composition and crystalline structure.

Q8: How are sedimentary rocks formed?
Ans: Sedimentary rocks are formed from the accumulation and compaction of layers of sediment over time.

Q9: What are metamorphic rocks?
Ans: Metamorphic rocks are formed when existing rocks are subjected to high heat and pressure, causing them to change their form and structure.

Q10: Explain the rock cycle.
Ans: The rock cycle is a continuous process where rocks are formed, broken down, and transformed into different types of rocks through various geological processes.

Long Answer Questions

Q1: Discuss the structure and composition of the Earth's core.
Ans: The Earth's core is divided into two parts: the outer core and the inner core. The outer core is made of liquid iron and nickel, while the inner core is solid and composed mainly of iron. The core is the hottest and densest part of the Earth.

Q2: Explain the formation of igneous rocks and provide examples.
Ans: Igneous rocks are formed from the cooling and solidification of molten magma or lava. Examples of igneous rocks include granite, basalt, and obsidian.

Q3: Compare and contrast the characteristics of igneous, sedimentary, and metamorphic rocks.
Ans: Igneous rocks are formed from magma and have a crystalline structure. Sedimentary rocks are formed from the accumulation of sediment and may contain fossils. Metamorphic rocks are formed from the transformation of existing rocks under high heat and pressure.

Q4. How do minerals contribute to human civilization?
Ans: Minerals are used in various industries for manufacturing products such as construction materials, electronics, and fertilizers. They also provide valuable resources like metals and gemstones.

Q5: Describe the significance of fossils found in rocks.
Ans: Fossils found in rocks provide evidence of past life forms and help scientists understand the history of the Earth and the evolution of different species.

Q6: Elaborate on the uses of rocks and minerals in various industries.
Ans: Rocks and minerals are used in construction, agriculture, manufacturing, and energy production. For example, limestone is used in building materials, quartz is used in electronics, and coal is used for energy generation.

Q7: Illustrate the process of metamorphism and its effects on rocks.
Ans: Metamorphism occurs when existing rocks are subjected to high heat and pressure, causing them to recrystallize and change their form. This process can result in the formation of new minerals and the development of foliation in rocks.

Q8: How does the rock cycle demonstrate the interconnectedness of rock formations?
Ans: The rock cycle shows how different types of rocks are continuously formed, broken down, and transformed into other types of rocks through various geological processes. It demonstrates that all rocks are interconnected and can undergo changes over time.

Q9: Examine the role of the Sun's energy in the rock cycle.
Ans: The Sun's energy plays a crucial role in the rock cycle as it drives the processes of weathering, erosion, and transportation of rocks and sediments. It also provides the heat necessary for metamorphism and the melting of rocks.

Q10: Discuss the importance of studying the Earth's structure and rocks in understanding our planet's history.
Ans: Studying the Earth's structure and rocks helps scientists understand how the planet formed, its geological processes, and its history over millions of years. It provides valuable information about the Earth's past climate, the evolution of life, and the occurrence of natural hazards.