Explanation

Comets are cosmic snowballs of frozen gases, rock and dust that orbit the Sun. 

When a comet's orbit brings it close to the Sun, it heats up and spews dust and gases into a giant glowing head larger than most planets.

Explanation

Carbon dioxide gas gives the beverage its sparkle and tangy taste and prevents spoilage.

Explanation

Elements can be classified as metals, metalloids, and nonmetals.

Explanation

Dry air from Earth's atmosphere contains 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and traces of hydrogen, helium, and other "noble" gases (by volume), but generally a variable amount of water vapor is also present, on average about 1% at sea level.

Explanation

The mass ratio of carbon to hydrogen in methane is 3:1.

methane formula:CH4 C:H 1:4

It requires 3 grams of Carbon for one gram of Hydrogen. So, for 36 grams of Carbon, we require 12 grams of Hydrogen.

Explanation

Lead is a chemical element.

Symbol Pb  and atomic number 82.

It is a heavy metal that is denser than most common materials.

Explanation

The atmosphere is comprised of layers based on temperature. These layers are the

troposphere

stratosphere

mesosphere 

thermosphere

A further region at about 500 km above the Earth's surface is called the exosphere.

Explanation

• Tungsten:
  
• • Tungsten is a heavy metallic element
  • Tungsten is also known as Wolfram,
  • which the element was first recognized by the English chemist Peter Woulfe.
    
  • It has the highest melting point
  • the highest tensile strength of any material.
  •  it has symbol W
  • Atomic number 74.
  • Tungsten is a rare metal found naturally on Earth
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Explanation

Answer: 

C: Heating of Mercuric oxide powder: The heating of Mercuric oxide powder is a permanent change. We cannot get powder by revere reaction so it is a chemical change

Sublimation of Iodine: It is a physical change

Heating a platinum wire in a Bunsen flame: Platinum is a noble gas that cannot change its physical appearance after heating. So it is not a chemical change

Evaporation of Alcohol: It is a physical change. The liquid is changed into gas 

Explanation

• The largest component of natural gas is methane
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• Natural Gas is also known as Methane.
• The principal use of methane is as a fuel.
• Natural gas also contains smaller amounts of natural gas liquids (NGLs, which are also hydrocarbon gas liquids)
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• Largest natural gas producer country in the world Russia
•  Russia is home to the world's largest natural gas reserves, with a total proved resource of 38 TCM

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