Answer:
a). The energy released by the alpha decay of 222 Rn is to 218 Po :
= 5.596 MeV
b).The energy of the alpha particle is 5.5 MeV
c) The recoil energy of Po = 0.096 MeV
Explanation:
The equation for the alpha decay of Rn to Polonium is:

The energy of the decay process can be calculated using:

= Change in the mass
Mass of Po = 218.008965 u
Mass of He = 4.002603 u
Mass of Rn = 222.017576 u
= mass of Po + mass of He - mass of Rn
= 4.002603 + 218.008965-222.017576
= - 0.006008


= -5.596 MeV
<u><em>The negative sign means energy is released during the process.</em></u>
b) The energy of the alpha particle is :



= 5.494 MeV
= 5.5 MeV
c).
Recoil energy: When the parent nucleus is at rest before the decay then , there must be the some recoil of daughter nucleus to conserve the momentum.This is termed as recoil energy.
<u><em>The energy of the recoil polonium atom :</em></u>
The formula for recoil energy is :
<em>The total energy - the kinetic energy</em>
<em>= 5.596 - 5.5 </em>
<em>= 0.096 MeV</em>
Answer:
MnO3 radical anion. Formula: MnO3- Molecular weight: 102.9368.
Answer:
Na₂CO₃.2H₂O
Explanation:
For the hydrated compound, let us denote is by Na₂CO₃.xH₂O
The unknown is the value of x which is the amount of water of crystallisation.
Given values:
Starting mass of hydrate i.e Na₂CO₃.xH₂O = 4.31g
Mass after heating (Na₂CO₃) = 3.22g
Mass of the water of crystallisation = (4.31-3.22)g = 1.09g
To determine the integer x, we find the number of moles of the anhydrous Na₂CO₃ and that of the water of crystallisation:
Number of moles = 
Molar mass of Na₂CO₃ =[(23x2) + 12 + (16x3)] = 106gmol⁻¹
Molar mass of H₂O = [(1x2) + (16)] = 18gmol⁻¹
Number of moles of Na₂CO₃ =
= 0.03mole
Number of moles of H₂O =
= 0.06mole
From the obtained number of moles:
Na₂CO₃ H₂O
0.03 0.06
Simplest
Ratio 0.03/0.03 0.03/0.06
1 2
Therefore, x = 2
Answer:
A is denser than B as it's volume for the same mass is smaller.
Explanation:
Hello.
In this case, we first need to take into account that the density of each metal A and B is computed by dividing the mass over the volume of each metal which is actually computed by substracting the volume of water from the volume of the water and the solid:

Next, we compute the densities as shown below:

In such a way, A is denser is B as it's volume for the same mass is smaller.
Best regards.
In the periodic table the lanthanoid and the actinides are place separately at the bottom because of their electronic configuration and their properties compared to the other elements.
The the lanthanoid and the actinides are place separately at the bottom in the periodic table due to their electronic configuration and the properties. and to make the periodic table more convenient . if we place the f block elements that is he lanthanoid and the actinides then the size of the periodic table will increase. the f block elements are called as the inner transition element.
Thus , to make the periodic table more convenient and to group the elements in the block the the lanthanoid and the actinides are place separately at the bottom.
To learn more about lanthanoid and actinide here
brainly.com/question/24390376
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