I assume this is a true or false question. I would say true
Neon, Helium, Krypton, Xenon, Argon
Two months later 13.8 milligrams of the barium-131 still be radioactive.
<h3>How is the decay rate of a radioactive substance expressed ? </h3>
It is expressed as:

where,
A = Amount remaining
A₀ = Initial Amount
t = time
T = Half life
Here
A₀ = 0.50g
t = 2 months = 60 days
T = 11.6 days
Now put the values in above expression we get



= 0.50 × 0.0277
= 0.0138 g
= 13.8 mg [1 mg = 1000 g]
Thus from the above conclusion we can say that Two months later 13.8 milligrams of the barium-131 still be radioactive.
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Question: Suppose that 0.50 grams of ban that 0.50 grams of barium-131 are administered orally to a patient. Approximately many milligrams of the barium would still be radioactive two months later? The half-life of barium-131 is 11.6 days.
Answer : The molar solubility of
is 
Explanation :
The solubility equilibrium reaction will be:

The expression for solubility constant for this reaction will be,
Let the molar solubility be, 'x'

Now put all the given values in this expression, we get:


Therefore, the molar solubility of
is 
Answer:
The outer core is the only layer that is liquid. It is also mainly made from nickel and iron. The main job of the outer core is that it's responsible for the Earth's magnetic field. As the earth spins, the liquid inside this layer spins aswell, keeping it balanced.