An alpha particle is best describe by:

^4He2, ^0e-1, ^0e+1, ^0e0

http://en.wikipedia.org/wiki/Alpha_particle

An alpha particle is best described by ^4He2.

To understand why, let's break down the notation. In nuclear or particle physics, the notation typically includes the mass number and the atomic number of the particle. The mass number is represented as a superscript at the upper left corner, and it denotes the total number of protons and neutrons in the nucleus of an atom or particle. The atomic number is written as a subscript at the lower left corner, and it represents the number of protons in the nucleus.

For an alpha particle, which consists of two protons and two neutrons, the mass number is 4 because it has two protons (2) and two neutrons (2), giving a total of 4.

The atomic number, which represents the number of protons, is 2 because there are two protons in an alpha particle.

Therefore, the correct notation for an alpha particle is ^4He2. The symbol 'He' represents the element helium, and the superscript 4 and subscript 2 indicate the mass number and atomic number, respectively.