♪⚝Sanjiv❀Jaiswal❁⩸

Statement: 

A chemical compound always contains the same elements combined together in the fixed ratio by weight, irrespective of the origin.

Law of reciprocal proportion relates the proportions in which elements combine across a number of different elements. It is also called as equivalent proportion. 

Example:

If element A combines with element B and also with C, if B and C combine together, the proportion by weight in which they do so will be simply related to the weights of B and C which separately combine with a constant weight of A.

Nitrogen combines with oxygen to form various oxide.

The ratio of different weight of oxygen 24, 40 combining with fixed weight of nitrogen 14 is 24:40 i.e. 3:5 which is simple whole number ratio. The given data illustrate the law of multiple proportions.

Statement:

"When two elements combine to form more than one compound, then the different weight of one element combining with a fixed weight of the other...

Atomic no. (Z) = 19 and Atomic mass (A) = 39
No. of neutrons = (A - Z) = (39 - 19) = 20
No. of electrons = Number of protons = Atomic number

The permanent change in which one compound is transformed into other compound have different properties is known as chemical change.

Two important characters are:

a. It is irreversible change.
b. New compound having different properties are formed.

Atomic no. (Z) = 13 and atomic mass (A) = 27
No. of neutrons = A-Z = 27 - 13 = 14
No. of electrons = 13 - 3 = 10

Al atom loses 3e^- to form Al⁺³.

सगरमाथा कलेजका विदयारथीहरूदवारा हावाको परभाव बिना पानी चुहिँदैन भनने कुरा परमाणित गरेर देखाइयो । उकत कलेजको परयोग शालामा समपनन कारयकरमका लागि सरवपरथम मुखतिर पवालैपवाल पारिएको टिनको बटटा र पानी लयायो। पछाडिपटटि चाहिँ एउटा मातर पवाल पारिएको टिनको बटटा र पानी लयायो। सबैभनदा पहिला उकत टिनको बटटाको पछाडिपटटिको पवाललाई औंलाले थुनियो र तयस बटटाभरि पानी भरियो । तयसपछि बटटालाई घोपटो पारेर हातले पछाडिको पवाल नखोली माथि उठाइयो तर तयहाँ पानी चुहिएन । जब औलाले बनद गरेको...