Question

Calcium, strontium and barium form a Dobereiner's triad . The atomic masses of calcium and barium are 40 and 137 respectively predict the atomic mass .
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Answer 1

Answer:

88.5

Explanation:

Ca+Ba/2

40+137/2

=177/2

=88.5

Answer 2

Given,

Three elements Calcium, strontium and barium form a Dobereiner's triad.

The atomic mass of Calcium = 40

The atomic mass of Barium are = 137

To find,

The predictable atomic mass of Strontium.

Solution,

We can simply solve this numerical problem by using the following process:

Let us assume that the predictable atomic mass of Strontium be x.

As per the principles of Dobereiner's triad;

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

Now, according to the question;

The atomic mass of Strontium is equal to the arithmetic mean of the atomic masses of Calcium and Barium

=> (Atomic mass of Calcium + Atomic mass of Barium)/2 = atomic mass of Strontium

=> (40+137)/2 = x

=> x = 177/2 = 88.5

=> predictable atomic mass of Strontium = 88.5

Hence, the predictable atomic mass of Strontium is equal to 88.5.