Introduction to light | Electronic structure of atoms | Chemistry | Khan Academy

You have probably had X-rays taken at the dentist's or doctor's office, but do you know how the X-ray images are made? Images made using X-rays, also called radiographs, are considered to be relatively safe to take, even though they are made using a small amount of radiation, specifically electromagnetic radiation. Radiation is energy that travels through space as either waves or high speed particles. Watch this video to learn more about electromagnetic radiation and X-rays. X-rays… Read more

Have you ever wondered how X-rays affect living organisms? You have probably had X-rays taken at the dentist's or doctor's office. These X-rays are considered to be relatively safe, but every X-ray exposes a person to some radiation, specifically electromagnetic radiation. Radiation is energy that travels through space as either waves or high speed particles. Watch this video to learn more about electromagnetic radiation. When the energy in X-rays encounters an object, it can… Read more

We encounter an amazing array of colors every day, from the greens of plants and the many colors of their flowers, to the pinkish blue of a sunset, to the artificial coloring in beverages. How do we perceive all of these colors? When light hits an object, some of that light is absorbed by the object, and the light that is not absorbed is what we see. In this science project, you will build a simple spectrophotometer from a cell phone and use it to investigate how visible light is absorbed by… Read more

Do you realize that you are constantly bombarded by particles? You do not feel them, you cannot see, hear, or smell them, but they are always there! These particles — collectively called background radiation — might even travel through you without ever interacting with the molecules in your body. In this science project, you will build your own cloud chamber to prove the existence of background radiation. You will then use your cloud chamber to determine if the background… Read more