Chemistry problem

[saleena]

John Dalton was the scientists who found what really matter was.ACCORDING TO HIS ATOMIC THEORY
1 Atom is the smallest particle that matter can be broken to
2 When atoms chemically combine forming compounds they always do so in simple and wholenumber ratio
3 Similar atoms can be grouped into element
4 All atoms in an element is identical,but atoms are of different elements are entirely different from one another
5 An element cannot be converted into another during a chemical reaction
today the only fact that remains true is that atoms are very small


How are the other facts considered to be false according to the today understanding?

 

[saleena]

please give me help

 

[destined007]

Why the points are wrong:
1) Atom can be further divided in proton, neutron and electrons. Although protons can be further divided into quarks but this is not part of A level syllabus so leave it.
2) This statement is somewhat true for simple computing but, for example, if one tried to demonstrate it using the hydrocarbons decane (chemical formula C10H22) and undecane (C11H24), one would find that 100 grams of carbon could react with 18.46 grams of hydrogen to produce decane or with 18.31 grams of hydrogen to produce undecane, for a ratio of hydrogen masses of 121:120, which is hardly a ratio of "small" whole numbers.
3) Iron and Florine are different atoms but both are considered as elements.
4) Carbon has two isotopes C12, C13 and C14. Although they are all carbon elements but not identical.
5) In fission, uranium is converted into krypton and barium which are completely different elements.

 

[madan159]

can anyone provide me information of Biochemistry in pdf files.