eg. Why isn t methane H4C, or carbon dioxide O2C instead of CO2
2006-09-23 21:06:18 · 25 answers · asked by anthony r 1 in Science & Mathematics ➔ Chemistry
its about the potencial of Electrode.
O always before F
and all metal always before the non metal
2006-09-23 22:13:18 · answer #1 · answered by Papilio paris 5 · 2⤊ 0⤋
When elements combine they always try to get 8 eletrons on their outer shell whether by losing them, gaining more electrons or by sharing.
In the case of Carbon Dioxide (CO2), the carbon has 4 electrons an needs to gain four more while the oxygen has 2 which it needs to lose. When the oxygen gives up its two electrons to the carbon, the carbon will then have 6 but will still need another two eletrons to make 8.
Therfore, another oxgygen is provided, and it renders its two electrons to the carbon so it now has 8 and is full.
This is the reason why u see the 2 behind O in CO2 because two oxygen molecules are used. No number is directly behind the carbon because only 1 carbon atom is used.
If 2 was behind the Carbon , it wud be saying a completely different thing.
Thats the reason why the numbers have to be at one specific point in a compound. Because they represent the number of atoms of that compound which is used........
Hope its a lil' clearer to you now...
2006-10-01 09:39:04 · answer #2 · answered by J D 3 · 0⤊ 0⤋
Chemical Symbol Ch4
2017-01-14 14:54:56 · answer #3 · answered by barnhart 4 · 0⤊ 0⤋
The number is placed after the relevent element by convention.
From your examples I assume you are more interested in the reason for the ordering of the elements, which i believe is to indicate structural information.
If formaldehyde is used as an example it is conventionally written HCHO. This may seem a bit unusual but writing it in this way shows the the compound is an aldehyde, due to the CHO. If you see OH it implies that you are either dealing with an alcohol or a hydroxyl group.
With regards to inorganic chemistry i believe the order is connected to the oxidation state of the particular atoms. In the case of H2SO4 the hydrogen have largely lost their electrons to the sulphur, S, in NaBH4 the hydrogen has largely gained an additional electron from the boron, B.
2006-09-27 19:22:55 · answer #4 · answered by propheticwalnut 3 · 0⤊ 0⤋
Each capital letter refers to a new element. For example "O" is the symbol for oxygen.
If there were two oxygen atoms joined together, then it would be O2.
In helium, the symbol is He, NOT HE- each capital letter represents a new element.
The number of atoms is always after the element- so in the example H2O, there are 2 hydrogen particles. After the "O" there are no numbers, so it counts as 1 oxygen atom.
Methane is CH4- that means 1 Crabon, and 4 hydrogens atoms.
Methane cannot be H4C, because that would mean there are 4 Hydrogen atoms, and 1 Carbon particle.
hang on... i see your point...
whoops... why can't they be the other way around? i dunno.
Soz i had a dumb blonde moment
2006-09-26 08:56:07 · answer #5 · answered by america_home_to_the_obese_peeps 2 · 0⤊ 0⤋
the numbers show the number of the element
eg. H2O contains 2 hydrogens and 1 oxygen
CO2 = one carbon and 2 oxygens
methane is CH4 as there is one carbon to which 4 hydrogens are bonded to.
2006-09-30 02:39:42 · answer #6 · answered by Anonymous · 0⤊ 0⤋
In a chemical formula, the name of the atom, is followed by the number of that particular atom, in a molecule. For instance H2O means that there are two parts Hydrgen (H), and since there is no number after the O we can assume that there is only one atom of Oxygen in a water Molecule.
Sugar C6 H12 O6 ... 6 atoms of Carbon (C), 12 atoms of Hydrogen (H), and 6 atoms of Oxygen (O).... I hope this helps
2006-10-01 14:47:12 · answer #7 · answered by Opus 3 · 0⤊ 0⤋
the number just tells how much of the element is present in hte compound. usually we write the compound as such, CH4, and not H4C because the convention is to write the central atom first before the substituents. so for methane, CH4, the the central metal atom is C and the substituent is H. the exception to this rule is water, H2O
2006-09-24 02:01:22 · answer #8 · answered by teroy 4 · 1⤊ 0⤋
the number after an element indicates the number of atoms of that element present in the compound. so, h2o means 2 hydrogen atoms to one oxygen and ch4 means there are four hydrogen atoms to one carbon atom. it depends on how many sites are available for other atoms to attach to. oxygen has two and so can have two hydrogens attached. in the case of co2, carbon has four sites available for bonding Ie ch4, but in the case of co2, oxygen has 2 sites available and carbon 4, so one carbon can bond to two oxygens or cobversely, 4 hydrogens.
2006-10-01 07:56:51 · answer #9 · answered by frankiethebear2002 2 · 0⤊ 0⤋
Never thought of that before. I'm curious now
In ionic compounds the positively charged ion always seems to come first, NaCl, H2SO4, NaOH. Generally you write the atom around which the others are centred first so CH4, C2H5OH etc. H2O seems to be the exception to that, but hydrogen is more electropositive than oxygen. I think it's just one of those things people just do without thinking about it.
2006-09-23 22:19:24 · answer #10 · answered by Ellie 4 · 1⤊ 0⤋
It's usually in alphabetical order, e.g. H is before O so it would be H2O rather than O2H
also, it wouldn't be O2H because there is only 1 oxygen atom combined with 2 hydrogens. so the 2 has to go afta H, and the O goes after the 2 (and H) because of the alphabet
2006-09-23 21:10:05 · answer #11 · answered by bobjella 1 · 0⤊ 1⤋