Grade 12 Chemistry
Complete the following equations:
e) 239 94 Pu + 4 2 He = ? + 3 1 0 n
The equation can be balanced as follows:
239 94 Pu + 4 2 He → 243 96 Cm + 1 0 n
To complete the equation, we need to balance the number of protons and neutrons on both sides.
First, let's identify the elements involved in the equation:
- 23994Pu represents the isotope Plutonium-239, with 94 protons and 239 - 94 = 145 neutrons.
- 42He represents the isotope Helium-4, with 2 protons and 4 - 2 = 2 neutrons.
- ? represents the unknown element.
- 310n represents three neutrons.
Since the number of protons must be conserved in a balanced nuclear equation, the sum of protons on the reactant side must equal the sum of protons on the product side.
On the reactant side, we have:
94 protons from Pu
2 protons from He
The total number of protons on the reactant side is 94 + 2 = 96.
On the product side, ? represents an unknown element, so we don't know the number of protons yet. However, we know that the sum of protons on both sides should be equal, so the unknown element should have 96 protons.
Now let's balance the neutrons:
On the reactant side, we have:
145 neutrons from Pu
2 neutrons from He
3 neutrons from 310n
The total number of neutrons on the reactant side is 145 + 2 + 3 = 150.
On the product side, we have:
The unknown element should have 150 - 96 = 54 neutrons.
In summary, the balanced equation is:
239 94 Pu + 4 2 He = ? + 3 1 0 n
Where the product "?":
- has 96 protons
- has 54 neutrons
To complete the given equation, we need to balance the number of protons and neutrons on both sides.
Let's break down the equation and identify the elements involved:
Reactant:
- 239 94 Pu (plutonium): This is an isotope of plutonium with atomic number 94 and mass number 239.
- 4 2 He (helium): This is an isotope of helium with atomic number 2 and mass number 4.
Product:
- ? (unknown): We need to determine the product element.
- 3 1 0 n (neutron): This is a neutron with atomic number 0 and mass number 1.
Now let's balance the equation by ensuring the total atomic numbers and mass numbers are equal on both sides:
Reactant:
239 94 Pu + 4 2 He
Product:
? + 3 1 0 n
There are two ways this reaction can occur:
1. Alpha decay:
In alpha decay, a helium nucleus (4 2 He) is emitted as a product. The product, in this case, will be an element with an atomic number two less than the reactant.
Therefore, the balanced equation would be:
239 94 Pu + 4 2 He -> 235 92 U + 3 1 0 n
2. Neutron-induced fission:
In this process, plutonium-239 captures a neutron (3 1 0 n), undergoes fission, and produces two daughter nuclei. To balance the equation, we need to determine the two daughter nuclei.
Therefore, the balanced equation would be:
239 94 Pu + 4 2 He -> 2? + 3 1 0 n
In neutron-induced fission, the specific daughter nuclei depend on the condition, energy of the neutron, and the isotope. The unknown element in this reaction can vary.
So, depending on the specific condition or context of the question, the final balanced equation would be:
239 94 Pu + 4 2 He -> 235 92 U + 3 1 0 n (in case of alpha decay)
239 94 Pu + 4 2 He -> 2? + 3 1 0 n (in case of neutron-induced fission)