To represent an alpha particle, we must recognize that an alpha particle is a type of ionizing radiation that is composed of 2 protons and 2 neutrons. This makes it a helium nucleus. The correct notation for a helium nucleus is:
[tex]\[ {}_2^4 \text{He} \][/tex]
Here:
- The subscript (2) represents the atomic number, which indicates the number of protons.
- The superscript (4) represents the mass number, which is the total number of protons and neutrons.
Given the options:
A. [tex]${ }_{-1}^0 \beta$[/tex]
- This notation represents a beta particle, specifically a beta-minus particle (an electron).
B. [tex]$y$[/tex]
- This does not represent any standard particle in nuclear physics.
C. [tex]${ }_2^4 He$[/tex]
- This is the correct representation of an alpha particle.
D. [tex]${ }_1^0 n$[/tex]
- This notation represents a neutron.
Therefore, the correct answer is:
C. [tex]${ }_2^4 He$[/tex]