Question

state and explain the law of dobereiner traids

Answer 1

According to Dobereiner, all elements occurred in groups of three, when arranged in increasing order of atomic masses. He referred to these groups as triads. In a traid the elements had similar chemical properties.  

Traids of the Dobereiners classification:

Traid1:

Element

Atomic mass

Lithium  (Li)

7

Sodium (Na)

23

Potassium (K)

39

Traid2:

Element

Atomic mass

Chlorine (Cl)

35.5

Bromine (Br)

80

Iodine (I)

127

Traid3:

Element

Atomic mass

Calcium (Ca)

40

Strontium (Sr)

88

Barium (Ba)

137

Dobereiner’s law of triads states that, the atomic mass of the middle element of a triad is the arithmetic mean of the atomic masses of the other two elements.

 

Example:

In the triad of lithium, sodium and potassium. The atomic mass of lithium is 7 and  the atomic mass of potassium is 39. The average of masses of lithium and potassium gives atomic mass of sodium 23.  

Answer 2

hey

here is answer

Dobereiner's traids

when elements are arranged in order of increasing atomic masses group of three elements( known as traits) having similar chemical properties are obtained.

the atomic mass of middle element of traids is equal to the arithmetic mean of other two elements.

limitations.

1. it failed to arrange all the then known elements in the form of traids.

2. dobereiner's code identify only three traids from the then known elements

hope it helps

thanks