Practice MCQ Questions and answers on Chemistry-GK

Car exhaust fumes contain many different things. Some of them are harmful to our health. This question asks about the parts that can cause cancer.

Option A: Oxides of nitrogen: These are gases that can irritate your lungs, but they are not directly known to cause cancer.

Option B: Carbon monoxide: This is a poisonous gas that stops your body from getting enough oxygen. It is dangerous but doesn't cause cancer directly.

Option C: Polycyclic hydrocarbons: These are a group of chemicals found in car exhaust. They are known to cause cancer.

Option D: Lead: Lead is a heavy metal, and it's toxic. While it can cause other health problems, it is not directly a known cancer-causing agent in the way polycyclic hydrocarbons are.

Therefore, the correct answer is C, Polycyclic hydrocarbons.

Acid rain is a formed due to the mixing of oxides of several harmful gases with the rain. Acid rain formation result from both natural sources, such as volcanoes and decaying vegetation, and man-made sources, primarily emissions of sulfur dioxide and nitrogen oxides resulting from fossil fuel combustion. These gases react in the atmosphere with water, oxygen, and other chemicals to form various acidic compounds. When this rain falls on the soil, the soil becomes acidic. Also, the leaves get destroyed and germinating seeds get corroded. Plants experience stunted growth. Thus, vegetation is destroyed. So, the correct answer is option D.

Lead pollution primarily came from cars in the past. Today, lead pollution primarily comes from lead smelters, metal processing plants and incinerators. Deposits of lead in soil can harm both humans and animals by absorbing it into a body.

The six air pollutants are carbon monoxide, lead, ground-level ozone, nitrogen dioxide, particulate matter, and sulfur dioxide.The combustion of gasoline and other hydrocarbon fuels in automobiles, trucks, and jet airplanes produces several primary air pollutants. Nitrous oxide (N₂O), commonly known as laughing gas, is used in surgery and dentistry for its anaesthetic and analgesic effects.

Cars burn fuel to run. When fuel burns completely, it mainly produces carbon dioxide (CO2).
However, when the burning isn't perfect (like when a car isn't well-maintained), other things are also produced.
One very important one is carbon monoxide (CO). This is a poisonous gas.
Other things found in car exhaust include nitrogen oxides (NO) and unburnt hydrocarbons.
But, of the choices given, carbon monoxide (CO) is a major component of automobile exhaust, often present in higher amounts than the others due to incomplete combustion.
Therefore, the correct answer is A: CO.

Photochemical smog is caused by oxides of sulphur and nitrogen.

Ozone depletion occurs when chlorofluorocarbons (CFCs) and halons—gases formerly found in aerosol spray cans and refrigerants—are released into the atmosphere.

The M shell only holds eight electrons. The M shell can actually hold up to 18 electrons as you move to higher atomic numbers. The maximum number of electrons you will find in any shell is 32.

The atoms of different elements have different numbers of electrons, protons, and neutrons. Every element is unique and has an atomic number. That number tells you the number of protons in every atom of the element. The atomic number is also called the proton number.