Answer:
A molecule is defined as two or more atom of same element or different element grouped together
When collecting a gas over water, the gas is always a mixture of the gas collected and water vapor. This statement is True
Water vapour or aqueous vapour is the name for the gaseous state of water. It is a particular kind of water condition inside the hydrosphere. Both the boiling and evaporation of liquid water as well as the sublimation of ice can produce water vapour. Water vapour is transparent, like the bulk of other atmospheric constituents. An example of water vapour is the mist that floats over a pot of boiling water.
<h3>What is Water vapor ?</h3>
The gaseous phase of water is known as water vapour, water vapour, or aqueous vapour. Within the hydrosphere, it is one type of water state. Water vapour can be created by the boiling or evaporation of liquid water as well as by the sublimation of ice. Like the majority of other atmospheric elements, water vapour is transparent.
Learn more about Water vapor here:
brainly.com/question/422363
#SPJ4

<u>Explanation:</u>
Velocity of B₁ = 4.3m/s
Velocity of B₂ = -4.3m/s
For perfectly elastic collision:, momentum is conserved

where,
m₁ = mass of Ball 1
m₂ = mass of Ball 2
v₁ = initial velocity of Ball 1
v₂ = initial velocity of ball 2
v'₁ = final velocity of ball 1
v'₂ = final velocity of ball 2
The final velocity of the balls after head on elastic collision would be

Substituting the velocities in the equation

If the masses of the ball is known then substitute the value in the above equation to get the final velocity of the ball.
Have you ever looked up the density of a substance ? You ought to try it. Go ahead. Pick a substance, then go online or open up an actual book and find its density. You will never see any particular volume mentioned along with the density . . . because it doesn't matter. The whole idea of density is that it describes the substance, no matter how much or how little you have of it. The density of a tiny drop of water under a microscope is the same as the density of a supertanker-ful of water.