Explanation

• When an object reflects all the component colors of light, it appears white.
• This is because the object is reflecting all the wavelengths of visible light, which are then perceived by our eyes as white.
• If an object absorbs all seven colors of light (i.e., all the wavelengths of visible light), it appears black.

Explanation

In the modern periodic table, there are 7 periods (horizontal rows) and 18 groups (vertical columns).

Explanation

• The speed of sound in air at sea level and 20°C (68°F) is approximately 343 meters per second.
  

The speeds of sound in different materials:

• Air: 343 m/s
• Water: 1433 m/s
• Wood: 3300-3600 m/s
• Brick: 4176 m/s
• Steel: 6100 m/s
• Diamond: 12000 m/s

Explanation

Explanation

A voltmeter is used to measure the potential difference (voltage) across two points in a circuit.

It is connected in parallel with the component whose voltage is being measured.

Explanation

The distance traveled by a body in unit time is called the speed of the body.

S.I. unit of speed is meter per second (ms−1).

ND11623

Explanation

The blood vessels that carry oxygenated blood away from the heart to the body are called arteries

The largest artery is the aorta, which branches out into smaller arteries that distribute oxygenated blood to different parts of the body. 

Explanation

• The mass number (A) is the sum of protons and neutrons present in the nucleus of an atom.
• It is a measure of the total number of nucleons (protons and neutrons) in the nucleus.

Explanation

Explanation

• Most of our nutrient absorption takes place in the small intestine.
• Where specialized enzymes and absorptive cells (enterocytes) break down.
• It absorb nutrients from food into the bloodstream.