Chapter 10 -

Question 1

How do you think life on Earth will change if there are no greenhouse gases on Earth?
Explain your answer.

Answer 1

Living things would die because it would be too cold

If there were no greenhouse gases on Earth, the planet’s temperature would be much lower than it is today. Greenhouse gases, such as carbon dioxide, water vapor, and methane, trap heat in the atmosphere, which keeps the Earth warm enough to support life as we know it.

Without greenhouse gases, the temperature on Earth would drop below freezing, and the planet would become uninhabitable for most life forms. This would have a profound impact on the planet’s ecosystems, as many species would be unable to survive in the extreme cold.

Additionally, the lack of greenhouse gases would impact the planet’s water cycle, as the absence of water vapor would mean less precipitation and a drier climate. This could lead to desertification in some areas and reduced agricultural productivity.

Overall, the absence of greenhouse gases would have a dramatic and negative impact on life on Earth, and it is essential to maintain a balance of these gases to support the planet’s delicate ecosystems.

Question 2

Briefly describe how the temperature of Earth’s atmosphere varies with the amount of greenhouse gases.

Answer 2

As the concentration of greenhouse gases increases, the temperature of Earth’s atmosphere increases.

The temperature of the Earth’s atmosphere is affected by the presence of greenhouse gases. These gases, such as carbon dioxide, methane, and water vapor, trap heat from the sun and prevent it from escaping back into space.

As the concentration of greenhouse gases increases in the atmosphere, more heat is trapped, causing the Earth’s temperature to rise. This phenomenon is commonly known as global warming or climate change.

Therefore, the more greenhouse gases there are in the atmosphere, the higher the Earth’s temperature will be. It’s essential to reduce greenhouse gas emissions to mitigate the impacts of climate change.

Question 3

What other changes do you think are likely to take place if the concentration of greenhouse gases in Earth’s atmosphere becomes too high?

Answer 3

When the concentration of greenhouse gases becomes too high, more heat will be trapped in Earth’s atmosphere, causing Earth to heat up even more.

If the concentration of greenhouse gases in Earth’s atmosphere becomes too high, it is likely that a range of other changes will occur

1. Sea level rise
2. Extreme Weather Events
3. Changes in Ecosystems
4. Human Heatlh Impacts
5. Economics Impacts
6. Ocean Acidification

Question 4

Suggest some human activities that can cause the concentration of greenhouse gases in the atmosphere to increase significantly from its naturally occurring level.

Answer 4

.Combusion of fossil fuels (coal, crude oil and natural gas)
.Combustion of solid waste, trees and wood products
.Other chemical reactions such as manufacturing of cement
.Combustion of fossil fuels and solid waste

There are several human activities that can significantly increase the concentration of greenhouse gases in the atmosphere. Here are some examples:

Burning fossil fuels: The burning of coal, oil, and natural gas releases carbon dioxide into the atmosphere. This is a significant contributor to the increased concentration of greenhouse gases.

Deforestation: Trees absorb carbon dioxide from the atmosphere, and when they are cut down, the carbon stored in them is released into the atmosphere.

Agriculture: Agriculture contributes to greenhouse gas emissions through livestock farming, fertilizer use, and changes in land use.

Industrial processes: Industrial processes, such as cement production and waste management, release greenhouse gases like carbon dioxide and methane into the atmosphere.

Transportation: Cars, trucks, airplanes, and other forms of transportation burn fossil fuels and emit carbon dioxide and other greenhouse gases into the atmosphere.

Energy production: Power plants that generate electricity using fossil fuels, such as coal-fired power plants, emit significant amounts of greenhouse gases.

Question 5

Metallic object and the non-metallic objects probably feel different.However they are of the same tempreture thus the feeling of “hotness” or “coldness” is not an accurate way of telling the temperature of an object.

Question 6

What is the SI unit for temperature?

Answer 6

The SI unit for temperature is the Kelvin (K).

Question 7

What does temperature measure?

Answer 7

Temperature is a measure of the degree of hotness or coldness of an object or substance. Specifically, it measures the average kinetic energy of the particles that make up the object or substance.

When the temperature of an object or substance increases, the particles that make up the object or substance move faster, and their kinetic energy increases. Conversely, when the temperature decreases, the particles move slower, and their kinetic energy decreases.

Temperature is an essential property of matter and has significant impacts on physical, chemical, and biological processes. It influences the behavior of materials, the rate of chemical reactions, and the growth and survival of organisms. Temperature is measured using a thermometer and is typically expressed in units of degrees Celsius (°C), Fahrenheit (°F), or Kelvin (K).

Question 8

What is a property of heat?

Answer 8

Heat always transfers from a region of higher temperature to a region of lower temperature. When you hold a cup of warm beverage (e.g. coffee), heat is transferred from the warm coffee (region of higher temperature) to your hand (region of lower temperature) through the cup. That is why your hand starts to feel warm.

note: When an object of higher temperature is in contact with an object of lower temperature, the heat energy will flow from the object of higher temperature to the object of lower temperature until both objects acquire the same temperature.

Heat is a form of energy that can be transferred between objects or systems. It is a property that describes the transfer of thermal energy from one object to another due to a temperature difference.

One of the main properties of heat is that it always flows from a hotter object to a colder object. This flow of heat is driven by the temperature difference between the two objects, with heat transferring from the hotter object to the colder object until both objects reach the same temperature.

Another property of heat is that it can cause changes in the physical or chemical properties of a substance. For example, when a solid is heated, it can melt and become a liquid, and when a liquid is heated, it can vaporize and become a gas. Heat can also cause chemical reactions to occur or change the properties of materials, such as their color, texture, or strength.

Heat is an essential property of matter and is involved in many natural processes, such as weather patterns, ocean currents, and the transfer of energy within the Earth’s interior. It is measured in units of energy, such as joules (J) or calories (cal), and is an important concept in fields such as physics, chemistry, and engineering.

Question 9

What are the three ways heat energy can be transferred from a region with a higher temperature to another region with a lower temperature?

Answer 9

Conduction, Convection and Radiation.

The three ways in which heat energy can be transferred from a region with a higher temperature to another region with a lower temperature are:

Conduction: Conduction is the transfer of heat energy from one object to another through direct physical contact. In this process, the heat energy flows from a region of higher temperature to a region of lower temperature through the material of the object. For example, when you touch a hot object, heat is transferred to your hand through conduction.

Convection: Convection is the transfer of heat energy through the movement of fluids or gases. When a fluid or gas is heated, it expands and becomes less dense, causing it to rise. As it rises, cooler fluid or gas moves in to take its place, and the cycle repeats. This movement of fluids or gases transfers heat energy from the hotter region to the cooler region. For example, the circulation of warm air rising and cool air sinking creates convection currents in the atmosphere.

Radiation: Radiation is the transfer of heat energy through electromagnetic waves. Unlike conduction and convection, radiation does not require a medium to transfer heat energy. Objects with a higher temperature emit electromagnetic waves that carry heat energy. When these waves come into contact with another object, the heat energy is transferred to the cooler object. For example, the heat you feel from the sun is due to the radiation of heat energy from the sun’s surface to the Earth.

These three methods of heat transfer are fundamental to many natural and human-made systems, including climate patterns, cooking, and heating and cooling systems.

Question 10

What is convection?

Answer 10

Convection is the transfer of heat energy from one place to another by the movement of the medium(for convection the medium can only be a liquid or gas and not a solid)

Question 11

What is radiation?

Answer 11

Radiation is the transfer of energy from a hotter body to a cooler body without the need for a medium

Question 12

What are some properties of conduction?

Answer 12

Heat transfer by conduction can occur in solids, liquids and gases, Conduction cannot take place in a vacuum.

Question 13

Why is conduction most effective (or fastest) in solids when compared to fluids (i.e., liquids and gases)?

Answer 13

The particles of solids are very closely packed. It means the transfer of energy from more energetic particles to less energetic particles by colliding is fastest and most effective.

Question 14

Why is conduction least effective (or slowest) in gases, when compared to solids and liquids?

Answer 14

The particles of gases are spaced very far apart. It means the transfer of energy from more energetic particles to less energetic particles by colliding cannot take place effectively.

Question 15

Why can convection occur in liquids and gases, but not in solids.

Answer 15

The particles of liquids and gases are free to move, unlike particles of solids which are fixed at their positions.

Note: Convection transfers heat from a region of higher temperature to a region of lower temperature, through the movement of the medium due to a difference in density, and it is only possible in fluids.

Question 16

Arrange the states of matter from the fastest rate of conduction to the slowest rate of conduction

Answer 16

solid➡️liquid➡️gas

Question 17

Why is the rate of conduction is fastest in solids when compared with liquids and gases?

Answer 17

The particles of solid are very closely packed. Hence, the transfer of heat by colliding into less energetic, neighbouring particles can take place very efficiently.

Question 18

Why is water a poor conductor of heat?

Answer 18

The particles of water are spaced further apart than the particles of solids. Hence, heat transfer by conduction in water is not as effective when compared to solids.

Question 19

It was mentioned that molten lava could reach a very high temperature. However, it cools down very rapidly despite its high temperature. Explain why

Answer 19

The molten lava cools down rapidly as it loses heat to the surroundings very rapidly, by the process of radiation.

From this real-life example, we know that the temperature of the objector substance affects the rate of heat transfer by radiation. The higher the temperature of the object or substance, the higher the rate of heat transfer by radiation.

Hence, the molten lava which is at a high temperature loses heat by radiation very rapidly to cool down within a short time.

Molten lava can reach temperatures of up to 1,250 to 2,200 degrees Fahrenheit (677 to 1,204 degrees Celsius), which is incredibly hot. However, when lava flows or erupts from a volcano, it quickly begins to cool down, often solidifying into solid rock in a matter of hours or days.

There are several reasons why lava cools down so quickly despite its high temperature. First, lava is often exposed to cooler air temperatures when it flows or erupts from a volcano. This can cause it to rapidly lose heat and cool down.

Second, lava is often in contact with cooler surfaces like the ground or water when it flows. This can also cause it to rapidly lose heat and solidify.

Finally, lava is often made up of minerals and other materials that have high melting points. This means that even though the lava itself is incredibly hot, the minerals and materials in it can begin to solidify and cool down quickly.

All of these factors contribute to the rapid cooling of lava, despite its high temperature. The exact cooling rate depends on a variety of factors, including the lava’s composition, the temperature of the surrounding environment, and the speed at which the lava is flowing or erupting.

Question 20

What can you infer about the rate of radiation from an elephant’s huge ears? What is the factor which affects the rate of radiation that you can associate with the huge ears?

Answer 20

The huge ears of the elephants help to keep them cool by losing heat energy at a faster rate via radiation.

The surface area of the object affects the rate of heat transfer by radiation.

The larger the ears, the larger the surface area. Hence, the elephants could lose heat energy at a faster rate via radiation with large ears.

Based on their size and shape, it can be inferred that an elephant’s huge ears are likely to play a role in regulating their body temperature by dissipating excess heat through radiation. The larger surface area of the ears means that more heat can be radiated away from the body, helping to cool the elephant down.

The rate of radiation from an elephant’s ears is affected by several factors, including the temperature of the surrounding environment, the temperature of the elephant’s body, and the size and shape of the ears themselves. When the ambient temperature is high and the elephant’s body temperature rises, the ears are likely to radiate more heat to help regulate the elephant’s internal temperature.

Additionally, the large surface area and thinness of an elephant’s ears allow for efficient radiation of heat. The blood vessels in the ears are also close to the surface, which helps to facilitate heat exchange between the blood and the environment.

Overall, the large size and shape of an elephant’s ears are an adaptation that allows them to regulate their body temperature in hot environments by increasing the rate of heat radiation from their bodies.

Question 21

What can you infer about the rate of radiation from an elephant’s rough skin? What is the factor which affects the rate of radiation that you can associate with the rough skin?

Answer 21

The rough skin of an elephant helps to keep it cool by losing heat energy at a faster rate via radiation.

The texture of the surface affects the rate of heat transfer by radiation.

The rougher the object’s surface, the higher the rate of heat transfer by radiation. Hence, an elephant could lose heat energy at a faster rate via radiation with a rough skin.

The rough skin of an elephant likely plays a role in regulating their body temperature by increasing the rate of heat radiation from their bodies. The surface area of an elephant’s skin is quite large, and its rough texture likely helps to create small air pockets that increase the surface area available for heat radiation.

The rate of radiation from an elephant’s rough skin is affected by several factors, including the temperature of the surrounding environment, the temperature of the elephant’s body, and the texture and thickness of the skin. When the ambient temperature is high and the elephant’s body temperature rises, the rough skin is likely to radiate more heat to help regulate the elephant’s internal temperature.

Additionally, the texture and thickness of the skin can affect the rate of radiation. Elephants have relatively thick skin, which may slow down the rate of heat transfer. However, the rough texture of the skin can help to offset this by increasing the surface area available for heat radiation.

Overall, the rough skin of an elephant is an adaptation that allows them to regulate their body temperature in hot environments by increasing the rate of heat radiation from their bodies.