Question

ANSWERS THE QUESTIONS IF YOU KNOW DON'T WRITE UNPROFITABLE THINGS ​

Answer 1

1. Dobereiner's law of triads states that 'arithmetic mean of the atomic masses of first and the third element in the triad should be equal to or at least almost equal to the atomic mass of the second element that is present in the triad'.

2. The law of triads was rejected because Doberiener failed to arrange all the known elements in form of triads. Besides, The law did not fully apply within the same family. II) Sodium is a very reactive metal . It is kept in kerosene to prevent it from coming in contact with moisture and oxygen to form Sodium hydroxide.

3.(i) This classification worked well for lighter elements only up to Ca. (ii) This classification gave us a relation between the properties of the elements and their atomic masses. (iii) It was shown by this classification for the first time that there exists a periodicity in the properties of the elements.

4.(i) This classification worked well for lighter elements only up to Ca. (ii) This classification gave us a relation between the properties of the elements and their atomic masses. (iii) It was shown by this classification for the first time that there exists a periodicity in the properties of the elements.

5. Newland's law of Octaves was discarded for the following reasons:

• Classification did not work with heavier elements beyond Calcium.

• Newland's classified two elements Cobalt and Nickel in the same slot, and these were placed in the same column as Fluorine, Chlorine and Bromine.