What is the main composition of air?

Air is mainly composed of oxygen and nitrogen.

Air is ___ and ___, allowing us to see through it.

Transparent and colorless

True or False: The atmosphere is a thick layer of air surrounding the Earth.

False. The atmosphere is a thin layer of air surrounding the Earth.

Fill in the blank: As we move higher in the atmosphere, the air becomes ___ .

Rarer

What is the definition of atmosphere in relation to air?

The atmosphere is the thin blanket of air that surrounds the surface of the Earth.

What is the primary gas that humans and animals need for respiration?

Oxygen is the primary gas required for respiration in humans and animals.

Air is composed of approximately what percentage of nitrogen?

Air contains about 78% nitrogen.

Fill in the blank: The presence of ___ in air is crucial for the water cycle.

Water vapour

True or False: Carbon dioxide is a larger component of air compared to oxygen.

False. Oxygen constitutes about 21% of air, while carbon dioxide is a smaller component.

Which process in plants requires carbon dioxide?

Photosynthesis requires carbon dioxide, which plants take in from the air.

What happens to water vapour in the air when it comes in contact with cold surfaces?

Water vapour condenses into droplets of water when it comes into contact with cold surfaces.

Fill in the blank: Dust particles can be observed in a beam of sunlight, especially in a ___ room.

Dark

What is the role of smoke in the air?

Smoke is a byproduct of burning fuel that contains harmful particles and gases, affecting health when inhaled.

True or False: Dust and smoke are not typically found in the air.

False. Dust and smoke are commonly present in the air.

What happens to dissolved air in water when it is heated?

When water is heated, the dissolved air escapes first before the water turns to vapor and begins to boil.

Fill in the blanks: Soil contains air, which is essential for the respiration of organisms living in it, and when water is added to dry soil, the air is displaced, creating ___.

Bubbles

True or False: Aquatic animals rely on the dissolved oxygen in water for respiration.

True

What role do burrows and holes created by soil-dwelling animals play in oxygen availability?

They allow air to move in and out of the soil, providing oxygen necessary for respiration.

Fill in the blank: Despite the continuous consumption of oxygen by many organisms, the atmosphere maintains its oxygen levels due to a natural process of oxygen ___.

Replenishment

Which process forces soil-dwelling organisms like earthworms to come to the surface to breathe?

Heavy rains that fill the spaces in the soil with water, displacing air.

What is the primary process through which oxygen is replaced in the atmosphere?

The primary process is photosynthesis, where plants produce oxygen as a byproduct while making their own food.