Answer:
9.31%
Explanation:
We are given that
Mass of KBr=49.3 g
Volume of solution=473 mL
Density of solution =1.12g/mL
We have to find the mass% of KBr.
Mass =
Using the formula
Mass of solution=
Mass % of KBr=
Mass % of KBr=
Mass % of KBr=9.31%
Hence, the mass% of KBr=9.31%
C: if it senses unequal currents
<span>Cobalt-60 is undergoing a radioactivity decay.
The formula of the decay is n=N(1/2)</span>∧(T/t).
<span>Where N </span>⇒ original mass of cobalt
<span> n </span>⇒ remaining mass of cobalt after 3 years
T ⇒ decaying period
t ⇒ half-life of cobalt.
So,
0.675 = 1 × 0.5∧(3/t)
log 0.675 = log 0.5∧(3/t)
3/t = log 0.675 ÷log 0.5
3/t= 0.567
t = 3÷0.567
= 5.290626524
the half-life of Cobalt-60 is 5.29 years.
<span>
</span><span>
</span>