Answer:
is the activity, measured in of a 50 mg sample of 90-Sr.
Explanation:
Half life of the 90-Sr ,
Activity coefficient of the 90-Sr = 

Mass of 90-Sr = 50 mg = 0.050 g
Molecular mass of 90-Sr = 90 g/mol
Moles of 90-Sr =
Number of atom in 0.0005555 moles of 90-Sr:


1 year = 
Activity measured in atoms per seconds:
= Number of atoms × 


Explanation:
I
have not yet learnt chemistry so sorry
Yes , CH3OH - this is methanol
<h3>Answer:</h3>
Curium-247 <em>i.e.</em> ²⁴⁷₉₆Cm
<h3>Explanation:</h3>
Alpha decay is given by following general equation,
ᵃₓA → ⁴₂He + ᵃ⁻⁴ₓ₋₂B
Where;
A = Parent Isotope
B = Daughter Isotope
ᵃ = Mass Number
ₓ = Atomic Number
Californium-251 is the parent isotope in our case and it has 98 protons (atomic number) and is given as,
²⁵¹₉₈Cf
The alpha decay reaction of Californium-251 will be as,
²⁵¹₉₈Cf → ⁴₂He + ²⁴⁷₉₆B
The symbol for B with atomic number 96 was found to be the atom of Curium (Cm) by inspecting periodic table. Hence, the final equation is as follow,
²⁵¹₉₈Cf → ⁴₂He + ²⁴⁷₉₆Cm
Answer:
Relative age is the age of a rock layer.
Absolute age is the numeric age of a layer of rocks or fossils.
Explanation: