Explanation

If Earth had no atmosphere, the sky would appear black even during the day,

Hence, the sky would appear black, just like it does from space.

Explanation

"Widow's Tears" is a common name for several plants

Most notably the Spiderwort (genus Tradescantia) and Dayflowers (genus Commelina),

Explanation

 The Stone Age is also known as the Paleolithic Period (Old Stone Age) for its earliest phase

Mesolithic (Middle Stone Age)

Neolithic (New Stone Age)

Chalcolithic Period (or Copper Age)

Explanation

Belief is defined as a state or habit of mind in which trust or confidence is placed in some person or thing.

It involves having a conviction that something is true or reliable. 

Explanation

Decibel (dB) measures the intensity or loudness of sound.

It is a logarithmic unit, meaning each 10 dB increase represents a tenfold increase in intensity.

Decibels are also used in electronics and signal strength measurements.

It does not measure speed of light or heat.

Common examples: Normal conversation ≈ 60 dB, threshold of hearing ≈ 0 dB, jet engine ≈ 120 dB.

Explanation

The volume of a sphere is the total space it occupies, calculated using the formula V = (4/3)πr³

V: Volume

π (Pi): A mathematical constant (approx. 3.14159).

r³ (Radius Cubed): The radius multiplied by itself three times (r × r × r). 

Explanation

Red-green color blindness is the most common type of color vision deficiency.

It affects the ability to distinguish between red and green colors.

It is sex-linked, occurring mostly in males due to inheritance on the X chromosome.

There are two main types: protanopia (red deficiency) and deuteranopia (green deficiency).

Explanation

One barrel of petroleum is a standard unit of measurement in the oil industry.

It equals 42 US gallons, which is approximately 159 liters.

In cubic meters, it is roughly 0.159 m³.

The UK gallon is larger, so one barrel equals about 34.97 UK gallons.

This unit is used worldwide for oil production, trading, and pricing

Explanation

Magma is molten rock beneath the Earth’s surface.

When it erupts through a volcano or reaches the surface, it is called lava.

Lava cools and solidifies to form igneous rocks.

The flow of lava can create volcanic landforms like lava plateaus and volcanic cones.

Lava temperature ranges from 700°C to 1,200°C, depending on its composition.

Explanation