One single molecule weighs almost nothing so why does out atmosphere weigh so much?

The weight of our atmosphere is due to the collective weight of a vast number of molecules. Here's a step-by-step explanation:

1. Understand the Composition: Our atmosphere is composed of a mixture of different gases, primarily nitrogen (78%) and oxygen (21%), with the remaining 1% consisting of argon, carbon dioxide, and other trace gases. Each of these gas molecules has a certain mass.

2. Consider the Quantity: While a single molecule of any of these gases weighs almost nothing, there are an estimated 1 x 10^44 molecules in the Earth's atmosphere. That's a 1 followed by 44 zeros! So, even though each individual molecule is incredibly light, the sheer number of them adds up.

3. Factor in Gravity: The weight of an object is its mass times the force of gravity. So, the weight of the atmosphere is the combined mass of all its molecules, multiplied by the force of Earth's gravity.

4. Add it All Up: When you add up the weight of all these molecules, pulled down by Earth's gravity, you get the total weight of the atmosphere. It's estimated to be about 5.5 quadrillion tons!

So, while a single molecule might weigh almost nothing, the combined weight of all the molecules in the atmosphere is enormous.