History

Question 1

Daltons Atomic Theory

Answer 1

1.Matter is composed of exceedingly small indivisible particles called
atoms; indivisible
2. An element consists of identical (one type of) atoms, that has a
mass that is characteristic of the element and is the same for all
atoms of that element.
3. Atoms of one element differ in properties from atoms of all other
elements.
4. A compound consists of atoms of two or more combined in a small,
whole number ratio. In a given compound, the numbers of atoms of
each elements are always present in the same ratio.
5. Atoms are neither created nor destroyed in a chemical reaction.
They are re-arranged to yield substances that are different from those
present before the reaction / change.

Question 2

Law of Definite Proportions

Answer 2

A compound consists of atoms of two or more combined in a small number ratio. In a given compound, the numbers of atoms of each element are always present in the same ratio.

Question 3

Law of Mass Conservation (Dalton Version)

Answer 3

Atoms are neither created nor destroyed in a chemical reaction. They are re-arranegd to yield substances that are different from those present before the reaction/ change.

Question 4

Law of Mulitple Proportions (Daltons Theory and Joseph Proust Experiment)

Answer 4

When two elements react to form more than one type of compound, a fixed mass of one element will react with masses of the other element in a ratio of small, whole numbers.

Question 5

Experiments: Cathode Ray by J.J. Thompson

Answer 5

Discovery of negatively charged electron and its mass: Charge ratio

Question 6

Oil-drop experiment by Millikan

Answer 6

Calculation of Charge of Election

Question 6

Models of Atom Developed

Answer 6

The ‘plum pudding’ annd lessons from the cosmos

Question 6

Experiment: Rutherfolds Gold Foil experiment

Answer 6

Nucleus and the Proton

Question 7

Experiments: Radioactivity by Becquerel, Curie, Chadwick

Answer 7

The neutron and Isotopes