Question

nuclear fusion practice

1. label the different atoms in the process of nuclear fusion below.

Explanation:

Step1: Identify Initial Particles

The small '+' symbols are protons, and the black circles are neutrons. The first step (top - two protons fusing) should form a deuterium nucleus? Wait, no, in nuclear fusion (like in stars, starting with hydrogen fusion). The first reaction: two protons ($^1_1\text{H}$) collide. But in the diagram, first, two protons (the '+' symbols) come together. But sometimes, one proton turns into a neutron (via beta - plus decay, but in the diagram, maybe the first fusion: two protons ($p$) → deuterium ($^2_1\text{H}$: 1 proton, 1 neutron), a positron, and a neutrino. But looking at the diagram, the first fusion (top left and top right) of two protons: maybe forming a deuterium? Wait, the next step: a proton and the deuterium? Wait, let's track the particles.

First, the top - most particles: two protons (each '+' is a proton). When they fuse (the star symbol), maybe we get a deuterium nucleus (1 proton, 1 neutron: so the symbol with a '+' and a black circle). Then, that deuterium (1p,1n) fuses with another proton (the '+' next to it). So deuterium ($^2_1\text{H}$) + proton ($^1_1\text{H}$) → helium - 3 ($^3_2\text{He}$: 2 protons, 1 neutron). Then, two helium - 3 nuclei fuse? Wait, no, in the diagram, the two middle - level nuclei (each with 2 protons and 1 neutron? Wait, no, let's count the protons and neutrons.

Let's label each stage:

1. Top - most: two protons ($^1_1\text{H}$) → fuse (first star) to form deuterium ($^2_1\text{H}$: 1 proton, 1 neutron). So the particle with a '+' and a black circle is deuterium.

1. Then, deuterium ($^2_1\text{H}$) fuses with a proton ($^1_1\text{H}$) (the '+' next to it) at the second star. So $^2_1\text{H}+^1_1\text{H}

ightarrow^3_2\text{He}$ (2 protons, 1 neutron). So the particle with two '+' and one black circle is helium - 3.

1. Then, two helium - 3 nuclei (each with 2p,1n) fuse at the bottom star. $^3_2\text{He}+^3_2\text{He}

ightarrow^4_2\text{He}+2^1_1\text{H}$. The final particle with two '+' and two black circles is helium - 4 ($^4_2\text{He}$), and the two '+' particles are protons.

Let's verify with the diagram:

• Top: two protons (p) → fuse to deuterium (p + n: $^2_1\text{H}$)
• Then, deuterium + p → helium - 3 (2p + n: $^3_2\text{He}$)
• Then, two helium - 3 → helium - 4 (2p + 2n: $^4_2\text{He}$) and two p.

So the labels should be:

• Top - most '+' : Proton ($^1_1\text{H}$)
• After first fusion (star) : Deuterium ($^2_1\text{H}$)
• The '+' next to deuterium: Proton ($^1_1\text{H}$)
• After second fusion (star) : Helium - 3 ($^3_2\text{He}$)
• After final fusion (star) : Helium - 4 ($^4_2\text{He}$) and Protons ($^1_1\text{H}$)

Step2: Match to Nuclear Fusion Stages

In the proton - proton chain (a common nuclear fusion process in stars), the steps are:

1. $^1_1\text{H}+^1_1\text{H}

ightarrow^2_1\text{H}+e^++
u_e$ (but in the diagram, maybe simplified, showing the nuclei without the positron and neutrino)

1. $^2_1\text{H}+^1_1\text{H}

ightarrow^3_2\text{He}+\gamma$

1. $^3_2\text{He}+^3_2\text{He}

ightarrow^4_2\text{He}+2^1_1\text{H}$

So the particles:

• The small '+' : Proton ($^1_1\text{H}$)
• The particle with 1 '+' and 1 black circle: Deuterium ($^2_1\text{H}$)
• The particle with 2 '+' and 1 black circle: Helium - 3 ($^3_2\text{He}$)
• The particle with 2 '+' and 2 black circles: Helium - 4 ($^4_2\text{He}$)

Answer:

• Top - most '+' : Proton ($\boldsymbol{^1_1\text{H}}$)
• After first fusion (star) : Deuterium ($\boldsymbol{^2_1\text{H}}$)
• The '+' next to deuterium: Proton ($\boldsymbol{^1_1\text{H}}$)
• After second fusion (star) : Helium - 3 ($\boldsymbol{^3_2\text{He}}$)
• After final fusion (star) : Helium - 4 ($\boldsymbol{^4_2\text{He}}$) and Protons ($\boldsymbol{^1_1\text{H}}$)