Distributed Block - View: Magazine: Latest Cover

cover of Nov. 28, 2015 Science News

Eureka! Lab

A place for discovery 
Bethany Brookshire

Eureka! Lab

Scientists Say: Radioactive

This word describes elements that shed energy over time

Eureka! Lab
glowing watches

These watch hands are glowing because they have been painted with radium. Radium is a radioactive element, which gives off energy that causes nearby zinc sulfide to glow green.

Mauswiesel/Wikimedia Commons/ (CC BY-SA 3.0)

Radioactive (adjective, “RAY-dee-oh-AK-tiv”)

This word describes unstable elements. Each atom — the basic unit of elements — has dense centers. This is its nucleus. Each nucleus is made of positively charged protons and neutrally charged neutrons. These particles are subatomic — meaning they are smaller than the atoms they are part of.  When an atom is radioactive, this nucleus sheds energetic protons and neutrons over time. Those particles deposit some of their energy along the path they travel. Because they can deliver so much energy onto a tiny area, these subatomic particles can pose a risk to cells.

In a sentence

Radioactive elements such as plutonium can be carcinogens — substances that cause cancer.

Follow Eureka! Lab on Twitter

Power Words

(for more about Power Words, click here)

atom   The basic unit of a chemical element. Atoms are made up of a dense nucleus that contains positively charged protons and neutrally charged neutrons. The nucleus is orbited by a cloud of negatively charged electrons.

cancer  Any of more than 100 different diseases, each characterized by the rapid, uncontrolled growth of abnormal cells. The development and growth of cancers, also known as malignancies, can lead to tumors, pain and death.

carcinogen  A substance, compound or other agent (such as radiation) that causes cancer.

neutron  A subatomic particle carrying no electric charge that is one of the basic pieces of matter. Neutrons belong to the family of particles known as hadrons.

nucleus  Plural is nuclei. (in biology) A dense structure present in many cells. Typically a single rounded structure encased within a membrane, the nucleus contains the genetic information. (in astronomy) The rocky body of a comet, sometimes carrying a jacket of ice or frozen gases. (in physics) The central core of an atom, containing most of its mass.

radioactive  An adjective that describes unstable elements, such as certain forms (isotopes) of uranium and plutonium. Such elements are said to be unstable because their nucleus sheds energy that is carried away by photons and/or and often one or more subatomic particles. This emission of energy is by a process known as radioactive decay.

radioactive decay  A process by which an element is converted into a lighter element through the shedding of subatomic particles (and energy).

subatomic  Anything smaller than an atom, which is the smallest bit of matter that has all the properties of whatever chemical element it is (like hydrogen, iron or calcium).

Readability Score: 
By Bethany Brookshire 7:00am, November 23, 2015
When two solutions are separated by a membrane where only the liquid can cross, the liquid will move from the side with a low concentration of dissolved materials to the side with a higher concentration. This movement has a special name.
By Bethany Brookshire 7:00am, November 19, 2015
American Chemical Society
Students love to see colorful fires in chemistry class. But a popular flaming-salts demo has resulted in some horrible injuries. Several groups warn of its dangers and propose a far safer version.
By Bethany Brookshire 7:00am, November 16, 2015
carbon dioxide
Carbon dioxide, sulfur dioxide and zirconium dioxide all have something in common. They are all molecules with two oxygens bound to some other element.
By Bethany Brookshire 7:00am, November 9, 2015
When brain cells need to communicate, they use chemicals as messengers. These molecules have a special name.
By Bethany Brookshire 7:00am, November 6, 2015
candy bar float
tir salt into water and make a candy bar float. Sure, it’s fun — but you can also make it research. You just need a big bag of candy and some measurements to turn this demo into an experiment with density.
By Bethany Brookshire 7:00am, November 2, 2015
mossy log
These days you might think organic refers just to food. But it has a completely different meaning in chemistry.
By Bethany Brookshire 7:00am, October 26, 2015
A quartile might sound like a fourth. But that’s not quite what it is.
By Bethany Brookshire 7:00am, October 22, 2015
Max Du
Many popular drinks contain caffeine — a stimulant that in high amounts can keep you up at night. One teen is now measuring just how much is in the beverages we drink.
By Bethany Brookshire 7:00am, October 19, 2015
jet stream
You might hear about the jet stream on a weather report, but what is it? We explain.
By Bethany Brookshire 7:00am, October 16, 2015
milk and cookie
One teen was dismayed to learn milk might host harmful pollutants. This prompted him to use his science fair project as a way to find out just what was in his favorite drink.
Subscribe to RSS - Eureka! Lab

From the SSP Newsroom

Science News


Science News for Students


Eureka! Lab