Yes, alpha particles are indeed considered to be helium atoms. An alpha particle consists of two protons and two neutrons bound together, which is the same composition as the nucleus of a helium atom. Therefore, in terms of its nuclear structure, an alpha particle can be viewed as a helium atom without its surrounding electrons.
However, it's important to note that while alpha particles possess the same nuclear composition as helium atoms, they do not exhibit the same properties as a complete helium atom. This is because the properties of an atom are determined by both its nucleus and its surrounding electrons.
The electrons in a helium atom contribute to its chemical properties, such as its reactivity and bonding behavior. Alpha particles, lacking electrons, do not participate in chemical reactions or exhibit any of the typical properties associated with atoms, such as ionization or the formation of chemical compounds.
In summary, alpha particles have a similar nuclear structure to helium atoms but lack the properties associated with a complete atom due to the absence of electrons.