C++ | MCQs

Explanation

salt (NaCl), sodium chloride, a mineral substance of great importance to human and animal health, as well as to industry. 

Formula: NaCl

Molar mass: 58.44 g/mol

Melting point: 801 °C

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ND30-12-2022

ND5-07-2023

Explanation

A chromosome is made up of proteins and DNA organized into genes.

Human somatic cells have 46 chromosomes (23 pairs).

These include 22 pairs of autosomes and 1 pair of sex chromosomes.

Explanation

The chemical formula of baking soda is NaHCO₃, which stands for sodium bicarbonate.

The chemical name of baking soda is sodium hydrogen carbonate or sodium bicarbonate (NaHCO3).

Sodium bicarbonate is non flammable

Baking soda is basic in nature.

Explanation

Oxidation is the loss of electrons during a reaction by a molecule, atom or ion.

Oxidation occurs when the oxidation state of a molecule, atom or ion is increased.

The opposite process is called reduction, which occurs when there is a gain of electrons or the oxidation state of an atom, molecule, or ion decreases.

Explanation

Heavy water, also known as Deuterium Oxide (D₂O).

It is used as a neutron moderator in nuclear reactors.

Due to its ability to slow down neutrons without absorbing them.

Explanation

The human cell contains 46 chromosomes.

These are organized into 23 pairs, where each parent contributes one chromosome to each pair, resulting in a total of 46 chromosomes in most human cells.

This number includes 22 pairs of autosomes and 1 pair of sex chromosomes, determining an individual's sex (XX for females and XY for males).

Explanation

Carbon dioxide is a colorless and non-flammable gas at normal temperature and pressure.

The bubbles in fizzy drinks are caused by carbon dioxide (CO2).

Soft drink manufacturers add fizz by dissolving carbon dioxide into the water at high pressures.

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Explanation

The largest cell in the human body is the female ovum.

The egg cell can be up to 100 micrometers (0.1 millimeters) in diameter, making it visible to the naked eye.

The smallest cell in the human body is the male gametes, that is, sperm

Explanation

The average distance between Earth and the Moon is approximately 384,400 km.

This distance can vary slightly due to the Moon's elliptical orbit around Earth.

Explanation

The blue colour of the sky is due to the scattering of light by the atmospheric particles.

Light of shorter wavelengths scatters more than the light of longer wavelengths and

the violet colour has a shorter wavelength, but our eyes are more sensitive to blue light. Hence, the colour of a clear sky is blue.