Here's why:

* Composition: An alpha particle is essentially a helium nucleus, consisting of two protons and two neutrons.

* Size: Compared to other subatomic particles like electrons, alpha particles are quite large. They have a much greater mass.

* Comparison: While an electron is almost massless, an alpha particle is about 7300 times heavier.

However, it's important to note that even alpha particles are incredibly small compared to everyday objects. They are microscopic!