Explanation

Number of moons in the planets:

Mercury: 0

Venus: 0

Earth: 1

Mars: 2

Jupiter: 95

Saturn: 146

Uranus: 27

Neptune: 14

Explanation

The moon is a satellite because it moves around Earth.

Earth and the moon are called "natural" satellites.

ND5-07-2023

Explanation

Silicon (Si) is the element most commonly used to fabricate solar cells and transistors.

Silicon is a semiconductor material that is widely used in the production of electronic components, including:

• Solar cells (photovoltaic cells)
• Transistors
• Microprocessors
• Diodes

Explanation

The speed of light traveling through a vacuum is exactly 299,792,458 meters (983,571,056 feet) per second. That's about 186,282 miles per second.

A universal constant is known in equations as "c," or light speed.

The speed of light in air is 2.9 × 10⁸ m/s.

Explanation

Non-renewable energy sources:

• Oil
  
• Nuclear energy
• Petroleum
• Natural gas & coal

Renewable sources of energy:

• Solar energy
• Wind energy
• Hydroelectric power
• Biomass energy
• Geothermal energy
• Tidal energy

Explanation

The universe is 13.7 billion years old with an uncertainty of 200 million years.

The WMAP model assumes that the universe's energy is made up of: 70% dark energy, 26% cold dark matter, and 4% atoms and photons

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

Jupiter, Uranus, and Neptune have rings, too.

But Saturn's rings are the biggest and brightest.

***

Explanation

A microscope is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. 

Explanation

Venus has a thick atmosphere primarily composed of carbon dioxide, with clouds of sulfuric acid

• Venus is the brightest planet.
• It has an atmosphere but no moons.
• It's identical in size, chemistry and gravity.
• It has volcanoes, mountains and sand.
• It's also called Sister Planet of the Earth.