Question

P, Q and R are three elements in a dobereiner's traid. If the atomic weight of P is 35.5 and r is 127 calculate the atomic number of Q.

Answer 1

Arthimatic mean of P , Q and R elements is 35.5 + 127 ÷ 2 = 81.25.

So atomic weight of Q = 81.25

Answer 2

Answer:

p=35.5

R=127

Explanation:

Atomic weight of Q = atomic weight of P+atomic weight of R/2

that is 162.5/2=99

so the correct answer is 81.25