In fusion, light nuclei merge — or " fuse" — to form one heavier nucleus.

在核聚变过程中，轻的原子核合并——或者“聚变”——形成一个较重的原子核。

Around 90% are protons, 9% are helium nuclei, and 1% are heavier nuclei.

约 90% 是质子， 9% 是氦核， 1% 是较重的原子核。

But to create heavier and heavier nuclei, you need more and more energy.

但是要制造越来越重的原子核，你需要越来越多的能量。

This fusion creates a heavier nucleus, and, crucially, releases an immense amount of energy, which eventually finds its way out of the Sun as heat and light.

这种聚变产生了一个更重的原子核，最重要的是，它释放了大量的能量，最终以热和光的形式离开太阳。

One reason is, as you can see on the mass-energy graph, light nuclei that fuse together undergo a much larger energy change than heavy nuclei that break apart.

原因之一是， 正如您在质能图上看到的那样，聚变在一起的轻核比分裂的重核经历的能量变化大得多。