Are you sure you copied that down correctly? I know what NH3 is but HJ I am comming up blank on. The only thing HJ I know is hebdojoule which is unit system.
Are you doing chemical balancing?
For every two AB produced, the reaction requires three A
12.5% of strontium-90 would remain in a sample after three half-lives have passed. Half-life automatically means 50% of the original amount would remain.
MH₂CO₃: (1g×2) + 12g + (16g×3) = 62 g/mol
1 mol --- 62g
0,8 mol -- X
X = 0,8×62
X = 49,6g
Answer is: <span>name of the product nuclide is thorium-230.
</span>
<span>Alpha particle is
nucleus of a helium-4 atom, which is made of
two protons and two neutrons.
²³</span>⁴U → ²³⁰Th + α (alpha
particle).
Alpha
decay is radioactive decay in which an atomic
nucleus emits an alpha particle (helium nucleus) and transforms
into an atom with an atomic number that is reduced by
two and mass number that is reduced by four.