Number of alpha decays is 4.
₉₀Th²³² → ₂He⁴ + ₈₈Ra²²⁸ ∴ α = ₂He⁴
Since, atomic number change by 2 in each alpha decay.
Total charge = 90 -82 = 8
Number of alpha decay = 8/2 = 4.
Alpha decay or α-decay is a type of radioactive decay wherein an atomic nucleus emits an alpha particle (helium nucleus) and thereby transforms or 'decays' into a extraordinary atomic nucleus, with a mass wide variety this is decreased through 4 and an atomic wide variety this is decreased through two.
Alpha decay - A common mode of radioactive decay wherein a nucleus emits an alpha particle (a helium-four nucleus). Beta decay - A commonplace mode of radioactive decay in which a nucleus emits beta particles. The daughter nucleus will have a better atomic number than the original nucleus.
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Answer:
3.46 x 10²⁴ molecules.
Explanation:
- <em>Knowing that every one mole of a substance contains Avogadro's no. of molecules (NA = 6.022 x 10²³).</em>
<em><u>Using cross multiplication:</u></em>
1.0 mole of HBr → 6.022 x 10²³ molecules.
5.75 mole of HBr → ??? molecules.
∴ The no. of molecules of HBr are in 5.75 mol = (6.022 x 10²³ molecules) ( 5.75 mole) / (1.0 mol) = 3.46 x 10²⁴ molecules.
By looking at the reaction, we can see that the reactants must absorb 315kJ of energy in order to form the reactants. This means that the reaction is absorbing energy, which would make it A. endothermic.
Hope this helps!
% mass of a solution is the mass of the solute present per 100 g of solution. It can be calculated using the formula,
Mass of solute = 4.92 g
Mass of solvent, water = 347 g
Total mass of solution = 347 g + 4.92 g = 351.92 g
Mass % of the solute = 
Therefore, the weight/weight % = 1.398 %
It is a simple stoichiometry problem. We have been given with balanced equation and 5.00 moles of HCl and have to calculate the moles of H2.
<span>From the balanced equation it is being clear that 2 moles of HCl are produced by 1 mole of H2. so, 1 mole of HCl will be produced by 1/2 moles of H2. So, the mole ratio of H2 and HCl is 1:2 </span>
<span>to calculate the moles of H2 for the given moles of HCl, multiply the moles of HCl by the mole ratio of H2 and HCl. </span>
<span>5.00 mole HCl x (1 mole H2/ 2 mole HCl) </span>
<span>= 2.50 mole H2 </span>
<span>so, to produce 5.00 moles of HCl, 2.50 moles of H2 are required.</span>
