Explanation

• The heart is the primary muscular organ
• Responsible for pumping blood
• Four chambers (two atria and two ventricles) that manage blood flow.
  It ensures that oxygen and nutrients are delivered to tissues and organs.

Last updated by NA on 23-April-2026

Explanation

The elements of the periodic table sorted by atomic number

Atomic number Name chemical element                 Symbol

1                         Hydrogen                                             H

2                         Helium                                                     He

3                         Lithium                                                      Li

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RY 15-01-2023

Explanation

Explanation

IRON:

• Symbol: Fe
• Atomic mass: 55.845 u
• Atomic number: 26
• Electron configuration: [Ar] 3d64s2
• Density: 7.874 g/cm³ (near room temperature)
• Electrons per shell: 2, 8, 14, 2
• Melting point: 1,538 °C

Explanation

Citric acid occurs naturally in:

• Lemons,
• Limes,
• Pineapples,
• Grapefruits,
• Berries (not blueberries),
• Tomatoes,
• Broccoli,
• Carrots,
• and some varieties of Peppers.

Explanation

Rust diseases of wheat, the most common these days is called leaf or brown rust and is caused by P. triticina Eriks.

Explanation

The empirical formula of glucose is CH2O.

This represents the simplest whole-number ratio of the elements in glucose.

It has a molecular formula of C6H12O6.

Explanation

• Structure of DNA was discovered by James Watson and Francis Crick in 1953.
• They discovered the double-helix structure of DNA using X-ray crystallography data.
• Their discovery revealed the double-helix structure of DNA, where two complementary strands are twisted together with sugar and phosphate molecules, and the nitrogenous bases (adenine, thymine, cytosine, and guanine) pair in a specific manner.

Explanation

The SI unit of volume is the cubic meter (m3), which is a derived unit.

1 m3 = 1 m • 1 m • 1 m.

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The SI unit of energy/work is the joule (J)

Explanation

Sulfur dioxide (SO₂) and nitrogen dioxide (NO₂) are primary precursors of acid rain.

Acid rain is a consequence of these atmospheric pollutants reacting with water, oxygen, and other chemicals to form acidic compounds. 

These acids contribute to environmental damage.