The answer to your question is letter D. Secured.
Yo sup??
Let the percentage of K-39 be x
then the percentage of K-40 is 100-(x+0.01)
We know that the net weight should be 39.5. Therefore we can say
(39*x+40*(100-(x+0.01))+38*0.01)/100=39.5
(since we are taking it in percent)
39*x+40*(100-(x+0.01))+38*0.01=3950
39x+4000-40x-0.4+0.38=3950
2x=49.98
x=24.99
=25 (approx)
Therefore K-39 is 25% in nature and K-40 is 75% in nature.
Hope this helps.
Answer : The partial pressure of the hydrogen is, 705.9 mmHg
Explanation :
According to the Dalton's law of partial pressure,

where,
= total pressure of the gas = 729.7 mmHg
= partial pressure of the hydrogen gas = ?
= partial pressure of the water = 23.8 mmHg (standard value)
Now put all the given values in the above expression, we get:


Therefore, the partial pressure of the hydrogen is, 705.9 mmHg
Metals are elements that are generally shiny when smooth and clean