Chemistry/Molecules

Okay, I have been wondering this for some time... Why do molecules (which make up everything) react the way they do to certain things?

 

Their physical properties determine this, such as charges, number of valence electrons, etc.

 

well that also has to do with what they are doesnt it? (please excuse me but im not taking chemistry, nor have I ever taken it) if it is then thats not really why... such as wind, why does air move? why does hot air rise? (of course i dont mean to answer these specific questions,but something like that)

 

Yes, it does have to do with what they are. What they are provides their properties.

Air moves in the form of wind because the sun heats the Earth's atmosphere unevenly, etc.

Hot air rises because it is less dense. One square foot of air weighs less than one square foot of cold air. If cold air is on top of hot air, since it weighs more, it will sink through the hot air, and vice versa.

 

Actually shredderbeam, it is not their physical properties. It is the arrangement of their electrons which change how they react, along with all their chemical properties.

 

True, but you could technically make that out to be physical properties. Electrons are physical, after all, and the sharing of them by two atoms is a physical act.

 

The electrons also affect the physical properties. I mean if it did not would the elements that are similar be similar if their valence electrons weren't the same?

 

Dont you do chemistry at school? The properties of an atom are determined nearly exclusively by the electron structure i.e. how many shells of electrons, how many electrons in the outer shell, if the atom is an ion (has more or less electrons than protons, all stable atoms have the same number of electrons as protons). The properties are what causes the atom to react to certain things i.e. an atom with one electron in the outer shell will react extremely quickly with other atoms.
Radioactive molecuoles on the other hand are determined by what isotope it is, i.e. how many more/less neutrons it has than a regular stable atom. If the neutron or mass number of the atom is different to the regular one then the atom will be extremely unstable and break apart, releasing radioactive particles which will then ionise other molecules, making them radioactive.

Yeah I had a chemistry gcse mock last week LOL

 

things react with other things based on their electronegitivity. ex: fluorine will react with anything and everything, tearing electrons off of everything in its path becasue its electronegitvity is VERY high

 

Shredder answered most of it but the second part has to do with densities hot air is lighter than "normal air" so it rises above it

 

The Z, it's not that hot air rises, it's that cold air, square foot for square foot, is heavier, so it displaces it upwards.