Chemistry
How does the Modern atomic theory contradict and correlate with Dalton's atomic theory?
Answer
Contradictions with Modern atomic theory:
| Dalton's atomic theory | Modern atomic theory |
|---|---|
| Atoms are indivisible particles. | Atoms are divisible into sub-atomic particles like protons, electrons and neutrons. |
| Atoms can neither be created nor be destroyed. | Atoms can be created and destroyed by nuclear fusion and fission. |
| The atoms of an element are alike in all respects, but they differ from the atoms of other atoms. | The atoms of an element may not be alike in all respects, as seen in the case of isotopes. |
| Atoms of elements combine in small whole numbers to form molecules. | In the formation of organic compounds, the numbers can be very big such as thousands. |
Correlation with Modern atomic theory:
The modern atomic theory however correlates with Dalton's atomic theory in the fact that atoms are the smallest unit of matter taking part in a chemical reaction and in a given compound the relative number and kind of atoms is a constant.
Related Questions
Complete the following table relating to the atomic structure of some elements.
Element Symbol Atomic Number Mass Number Number of Neutrons Number of Electrons Number of Protons Li 3 6 Cl 17 20 Na 12 11 Al 27 13 S 32 16 Give the use of the following isotopes:
(a) Radioactive isotopes
(b) 235U
(c) 60Co
(d) 131I
(e) 14C
Explain:
(a) octet rule for formation of a chemical compound.
(b) duplet rule for formation of hydrogen.
An element
A has atomic number 7, mass number 14
B has electronic configuration 2, 8, 8
C has 13 electrons, 14 neutrons
D has 18 protons 22 neutrons
E has electronic configuration 2, 8, 8, 1
State
(i) valency of each element
(ii) which one is a metal
(iii) which is a non-metal
(iv) which is an inert gas.