Then why will the molecules move apart when the gas is heated?Because when a gas, or a mixture of gases like air, is heated up the molecules move further apart, making it less dense.
All kinds of life: micro and macro organisms including the plant, animal and man (of course not the man of Earth, but I think he may be to much extent similar to Earth's man.What kind of life? An amoeba?
Then why will the molecules move apart when the gas is heated?
These are some observations, and you explain them in some way, but if you look carefully, you can realize another explanation is true, so you only take the surface appearance not the deep reason. And you will know the repelling between the hot molecules as the interpreter (who did not graduate at any primary school); he was right in his understanding. And that your British school is not the ultimate end of science.
I know all this.. but why don't you understand it in another way, which will also explain such observations correctly: the hot gas will repel the hot center of the earth. This explanation gives a better view and a better explanation of many other observations.All heat is is how fast the atoms in an object move. A warmer object means its atoms are moving faster than a colder object. In a solid, atoms stay in one place but vibrate. If you heat that object up the atoms vibrate faster. Once it reaches a certain temperature the atoms of the object are vibrating so much that they break free of the bonds holding them together as a solid and move freely about - so the solid is now a gas or a liquid. The same applies in gases and liquids - the hotter a gas or liquid is, the faster its atoms move. Moving around faster and more energetically means the atoms are more likely to move further apart from each other - which is why when you heat a gas it expands and becomes less dense.
When you pump hot air into a hot air balloon it cause the balloon to rise. This is because hot air is less dense than the cooler air around it so it rises up above the denser cooler air. Inside the hot air balloon, this rising of the less dense hot air pushes the balloon upwards.
So most solids are denser than liquids and most liquids are denser than gases. So when a solid becomes a liquid or a liquid becomes a gas it becomes less dense. One exception to the rule is water - water as a solid is less dense than it is as a liquid, which is why icebergs float. The fact that ice floats on water is actually a strange oddity.
I know all this.. but why don't you understand it in another way, which will also explain such observations correctly: the hot gas will repel the hot center of the earth. This explanation gives a better view and a better explanation of many other observations.
Moons of a moon!? It isn't logical;
I object to their logic, and you bring their same argument.