Explanation

About 97% of the Earth's water is contained in the oceans, which is saltwater.

The remaining 3% is freshwater, but most of it is frozen in glaciers and polar ice caps.

Only about 0.3% of the Earth's water is freshwater that is readily available for human consumption, agriculture, and other uses.

Explanation

Carbon monoxide is a toxic gas that interferes with the blood's ability to carry oxygen, making it harmful to humans.

It can cause symptoms like dizziness, nausea, and even death if inhaled in high concentrations.

Explanation

Nichrome, an alloy of nickel and chromium.

It is used because of its high resistance and ability to withstand high temperatures without oxidizing.

Explanation

Aluminum is the most abundant metal in the Earth's crust.

It comprising about 8% of its weight.

It is primarily found in the form of bauxite ore.

Explanation

• When red litmus paper is dipped in a basic solution, it turns blue.
• This indicates that the solution is basic, or alkaline.

Note: When blue litmus paper is dipped in an acid solution, it turns red.

Explanation

Washing soda, also known as sodium carbonate (Na₂CO₃).

It is made up of sodium (Na), carbon (C), and oxygen (O).

It is commonly used for cleaning purposes due to its ability to soften water and remove stains.

Explanation

Cracks on roads can occur due to expansion, contraction, and changes in temperature.

Expansion occurs when materials heat up and expand, while contraction happens when they cool down and shrink.

These changes in temperature can cause stress on the road surface, leading to cracks.

Explanation

Chlorofluorocarbons (CFCs) are chemical compounds that contain fluorine, carbon, and chlorine.

They were commonly used in refrigeration and air conditioning but are now regulated due to their role in ozone depletion.

Explanation

Condensation is the process where water vapor in clouds cools down as it moves through colder regions, turning into liquid water (rain) or solid ice (snow).

This process is a key part of the water cycle.

Explanation

Distillation is a technique used to separate a volatile substance (which evaporates easily) from a non-volatile substance by heating the mixture and condensing the vapor.

It is commonly used to purify liquids or separate components based on their boiling points.