Explanation

• A chemical reaction is a process in which one or more substances are converted into new substances, often with a change in chemical composition and properties.
• Chemical reactions involve the breaking and forming of chemical bonds, resulting in a transformation of the original substances.

Explanation

• Leaves changing colors in the fall is an example of a chemical reaction.
• During this process, the production of chlorophyll (the green pigment) slows down, and the production of other pigments.
• Like carotenoids and anthocyanins increases, causing the leaves to change color.

Explanation

• When a metal bubbles when placed in an unknown liquid, it indicates that a chemical reaction has taken place.
• Bubbling is often a result of a gas being released during a reaction.
• In this case, the metal is reacting with the unknown liquid to produce gas, causing the bubbling effect.
• This is a clear indication that a chemical reaction has occurred.

Explanation

• Deforestation is the permanent destruction of forests to make the land available for other uses.
• Such as agriculture, urbanization, and logging.

Explanation

• Giant pandas are an endangered species, due to habitat loss, low birth rates, and other factors.
• Conservation efforts are in place to protect this iconic species.

Explanation

• The poisonous gas which is the main byproduct of motor vehicles with an irritating smell is sulfur dioxide (SO₂).
• Sulfur dioxide is produced by the combustion of fossil fuels containing sulfur and contributes to air pollution and respiratory problems.

Explanation

Carbon monoxide (CO) is a colorless, odorless, and highly toxic gas that is emitted by the incomplete combustion of fossil fuels, such as gasoline, natural gas, and wood.

Explanation

• Global warming is the gradual increase in Earth's surface temperature, primarily caused by human activities releasing greenhouse gases. 
• It leads to rising temperatures, extreme weather events, and altered ecosystems.

Explanation

• Carbon dioxide (CO2) is produced when trees and fossil fuels are burned, through a process called combustion.
• Combustion releases carbon dioxide and water vapor into the atmosphere.

Explanation

• Acid rain affects the photosynthesis and growth of plants.
• Acid rain can alter soil chemistry and damage leaves, which in turn negatively impacts the photosynthesis process and overall plant health.