Antiparticles

For every single kind of subatomic particle, there is an antiparticle with the following properties:

• Equal rest mass.
• Opposite charge.
• Annihilates it and the particle when they meet, and convert their masses into photons.

Fundamental antiparticles

• Positrons ($_{-1}^0\beta$) are the antiparticle to electrons, as they have opposite charge ($ -e $) and equal rest mass.
• Antiprotons ($\overline{p}$) are the antiparticle to protons, as they have opposite charge ($ -e $ but equal rest mass.
• Antineutrons ($\overline{n}$) are the antiparticle to neutrons, as they have opposite charge (still $ 0 $) but equal rest mass.
• Antineutrinos ($\overline{v}$) are the antiparticle to neutrinos, as they have opposite charge (still $ 0 $) but equal rest mass.

Photons

Electromagnetic waves are emitted in packets that leave the source in various different directions; these packets are known as photons. Their energy can be calculated by:

$$E_p = hf = \frac{hc}{f}$$

The phlanck constant

$h = 6.63 \times 10^-34 Js$