Identify the missing particle in the following nuclear reactions

Question

Am 95 241 + He 24 → _________ + 2 n01 n 0 1 + U 92 235 → _________ + 2 n01 + Te 52 137 

Answer 1

The formatting of the answer seems to be bad. I think you've got two questions:

(1) Am 95 241 + He 2 4 -> _____ + 2 n 0 1

(2) n 0 1 + U 92 235 -> _____ + 2 n 0 1 + Te 52 137

Let's do these one at a time.

(1) Am 95 241 + He 2 4 -> _____ + 2 n 0 1

You've got the nuclear reaction with the atomic number AND weight for each particle, which is great and gives us everything we need to solve the missing product. You can see that your first reactant is "Am 95 241," which is americium, atomic number = 95 (which also equals the number of protons), and atomic weight (protons plus neutrons) equals 241. Your second reactant is helium, atomic number (and protons) = 2, weight (protons plus neutrons) = 4. The product you know is two neutrons--obviously, each one has no protons and one neutron. There's only one missing product.

The reaction doesn't include any particle changes (changes to antiparticles or creation of neutrinos), so the total number of protons in your reactants must equal the total number of protons in your products. The total atomic weight of your reactants must also equal the total atomic weight of your products.

To determine the number of protons in the missing product, we add up the protons in the reactants, and subtract the protons in the product that you know. Here's the same equation, with the important parts in bold:

Am 95 241 + He 2 4 -> _____ + 2 n 0 1

You can see there are 95 + 2 protons in the reactants, for a total of 97. The product you know has NO protons, so don't subtract anything from the 97 protons. The missing product has 97 protons.

Next, to determine the atomic weight of the missing product, do the same thing you just did with protons, but use the atomic weights instead:

Am 95 241 + He 2 4 -> _____ + 2 n 0 1

There are 241 + 4 nucleons in the reactants, for a total of 245. The product you know has one nucleon per particle, and there are TWO particles, so there are two nucleons accounted for with that product. 245 nucleons minus 2 nucleons gives you the atomic mass of the missing product: 243.

You know the missing product has 97 protons and a total mass of 243. Finally, look up the element with 97 protons on a periodic table to find out the name: berkelium, symbol Bk. Let's put the symbol, atomic number, and mass into the original equation, underlined, to show our answer:

Am 95 241 + He 2 4 -> Bk 97 243 + 2 n 0 1

On to the second reaction.

(2) n 0 1 + U 92 235 -> _____ + 2 n 0 1 + Te 52 137

We'll use the same method as above. Without re-explaining, here are the steps:

No particle changes are involved, so total protons will match on each side, and total atomic weight will match on each side.

Protons: 0 + 92 = 92 in reactants. 0 + 52 = 52 in known products. The missing product has 92 - 52 = 40 protons.

Atomic weight: 1 + 235 = 236 nucleons. 2 + 137 = 139 in known products. (You see there are TWO neutrons coming out, right?) The missing product has 236 - 139 = 97 nucleons.

We look up the atom with 40 protons and find that it is zirconium, symbol Zr.

Here's the answer for the second reaction, with the missing product underlined:

n 0 1 + U 92 235 -> Zr 40 97 + 2 n 0 1 + Te 52 137