why do atoms combine to form compunds?

Answer 1

An atom always wants to have 8 electrons in its outer shell (except for Helium and Hydrogen which want 2). An atom bonds with another atom so it can have a full shell. For example Oxygen has 6 electrons in its outer shell and Hydrogen has 1 , so if you put two Hydrogens and one Oygen together, the Oxygen will be able to have 8 part of the time and each Hydrogen will be able to have 2 part of the time.

Answer 2

Because they can. Atoms contain different numbers of electrons in "shells" surrounding the nucleus, in a very complex arrangement which requires advanced physics to understand. It's the outermost shell that participates in chemical reactions where different atoms share one or more electrons and stick together as a result.

Not all atoms form compounds easily. The "noble gases" on the right side of the Periodic Table have all of their electron shells filled, so their electrons are tightly bound to the nucleus and don't mix with other types of atoms (this is why they are called "noble," because nobles don't mix with the rest of us - true story).

Chemical compounds are electrical balancing acts between two and up to thousands of atoms. Carbon forms especially strong bonds because its outer shell is precisely half full, so it can lose or gain electrons with equal ease. Lucky for us, because we're made of carbon - or put another way, we wouldn't exist if the chemistry of carbon were any different than it is.

Answer 3

this is just coming from a chem student but i'm pretty sure it has to do with the single atoms needing to have a full shell of electrons and since only the noble gases (the ones all the way to the right on your periodic table) have that then the others share their electrons. Kinda like if you and your freind want a $100,000 car and you have 75,000 and your buddy has 25,000. You would share the car thus making it a compound car. get it?

P.S. my teacher really dooes use cars as models in chemistry. hes pretty cool!

Answer 4

The physical chemistry reason is that the compound, with the shared electrons orbiting all the nucleii, has a lower energy level than the sum of the isolated component atoms. That's why forming the compound releases energy.

Answer 5

All atoms try to form the same outer electron configuration as the noble gases. Because of this, cations (those with few valence electrons) try to give up their electrons to anions (those with a lot of valence electrons and only need a few to be like a noble gas).

The sub number in an ionic coumpouns shows how many of each ion there is, such as in Lithium Sulfide, Li2S, lithium gives up one electron, giving it a poisitive charge of one, and sulfer Tries to take in two electrons, giving it a negetive charge of two, so it requires two litium ions to form the ionic compound, hence the subscript of 2.

This is also useful in nomenclature when going from a name to a formula. You have Li - S 2+ just swap the number of charges to the other's subscript.
Li - S 2+ >> Li2S

Answer 6

well, atoms by it self are not very stable because its outer electron shell still has space to add more electrons. to make itself more stable, it combines with another atom to fill up those spaces. by filling up the spaces it will not be able to combine with any more atoms and will thus become stable. atoms will by nature always strive to become more stable either by combining with another or breaking down.

Answer 7

Propane is C3H8. you're a wee bit wanting hydrogen atoms, regardless of in case you tried to make propyne it would nonetheless no longer artwork, as you require one extra hydrognen atom.to artwork it.