Real-World Examples of Photons: Light, Radio Waves, and More

📚 Quick Study Guide

• 💡 Photons are elementary particles, the quanta of the electromagnetic field, including electromagnetic radiation such as light, radio waves, and X-rays.
• ⚡ Photons are always in motion and have no mass.
• 🌊 The energy of a photon is given by $E = hf$, where $E$ is energy, $h$ is Planck's constant ($6.626 \times 10^{-34} Js$), and $f$ is frequency.
• 🌈 Different frequencies of photons correspond to different types of electromagnetic radiation. For example, higher frequency photons are X-rays, while lower frequency photons are radio waves.
• ☀️ Light bulbs, the sun, lasers, and even your microwave emit photons.

🧪 Practice Quiz

1. What is a photon?
   1. A type of atom.
   2. A quantum of electromagnetic radiation.
   3. A type of electron.
   4. A form of dark matter.
2. What is a key property of photons?
   1. They have mass.
   2. They are always stationary.
   3. They are always in motion.
   4. They are affected by the strong nuclear force.
3. Which formula gives the energy of a photon?
   1. $E = mc^2$
   2. $E = hf$
   3. $E = \frac{1}{2}mv^2$
   4. $E = kT$
4. What type of electromagnetic radiation has photons with the highest frequency?
   1. Radio waves
   2. Microwaves
   3. Visible light
   4. X-rays
5. Which of the following emits photons?
   1. A black hole
   2. A light bulb
   3. Absolute zero temperature
   4. A vacuum
6. What happens to the energy of a photon as its frequency decreases?
   1. It increases.
   2. It decreases.
   3. It stays the same.
   4. It becomes infinite.
7. Which of the following is NOT an example of photons in the real world?
   1. Radio waves transmitting music.
   2. X-rays used in medical imaging.
   3. Sound waves traveling through air.
   4. Sunlight warming the Earth.