Answer:
8.625 grams of a 150 g sample of Thorium-234 would be left after 120.5 days
Explanation:
The nuclear half life represents the time taken for the initial amount of sample to reduce into half of its mass.
We have given that the half life of thorium-234 is 24.1 days. Then it takes 24.1 days for a Thorium-234 sample to reduced to half of its initial amount.
Initial amount of Thorium-234 available as per the question is 150 grams
So now we start with 150 grams of Thorium-234
So after 120.5 days the amount of sample that remains is 8.625g
In simpler way , we can use the below formula to find the sample left
Where
is the initial sample amount
n = the number of half-lives that pass in a given period of time.
Answer:
1.53x10^22 atoms of Au
Explanation:
To find the atoms of gold we need first, to convert the mass of gold to moles using molar mass of gold (196.97g/mol). Then, these moles must be converted to number of atoms based on definition of moles (1 mole = 6.022x10²³ atoms).
<em>Moles Au:</em>
5.00g Au * (1mol / 196.97g) = 0.0254 moles of Au
<em>Atoms of Au:</em>
0.0254 moles * (6.022x10²³ atoms / 1 mole) =
<h3>1.53x10^22 atoms of Au</h3>
The most soluble of the compounds given above is [NH4]3PO4. [NH4]3PO4 is a salt of ammonium and phosphate; it is a white crystal at room temprature. It is an highly unstable compound and thus easily decompose when mixed with water.