移动速度快的电子叫贝塔粒子。

The very fast electron is known as a beta particle.

较阿尔法粒子而言，贝塔粒子穿透力强很多。

Beta particles penetrate much farther through materials than alpha can.

很难想象原子核会弹射出贝塔粒子，更不要说重很多的氦气了。

Like the beta particle, you would not have expected a heavier nucleus to throw out helium.

被释放的贝塔粒子有足够的能量穿透人体并被监测到。

Beta particles are emitted and have enough energy to emerge from the body and be detected.

阿尔法粒子是贝塔粒子质量的8000倍，而速度要慢些。

An alpha particle is 8,000 times more massive than beta, and it's a bit slower.

除了阿尔法和贝塔粒子外，还有第三种辐射：其实不是粒子的伽马。

There is a third type of nuclear radiation: gamma, which is not a particle at all.