During the week of May 13th, the CO2 level at the Mauna Loa Observatory in Hawaii topped 400 ppm repeatedly. Daily levels of CO2 can vary due to weather, and there are seasonal trends as well. The level of atmospheric greenhouse gases continues to increase, now over 120 ppm since the Industrial Revolution began. For more on the Keeling Curve, see http://keelingcurve.ucsd.edu/. Find out more about greenhouse gases and warming.
The week of May 19 brings dozens of tornadoes to Tornado Alley in the states of Oklahoma, Kansas, Iowa, Illinois and Missouri. On May 20th, a massive tornado struck Moore, Oklahoma, devastating communities - destroying over 100 homes and hitting two elementary schools and a hospital - with many casualties and deaths. Our thoughts are with our friends and colleagues suffering from these storms. For more on the May 20th storms, see the NOAA Storm Prediction Center Storm Report.
This simplistic model of an atom shows protons as red spheres in the central nucleus. This model is NOT to scale; to match the scale of the nucleus the electrons (yellow) should be much smaller and much further away from the nucleus. Original artwork by Windows to the Universe staff (Randy Russell).
A proton is a type of tiny particle. All atoms have protons in them, along with electrons. Most atoms also have neutrons.
Protons and neutrons are just about the same size. However, protons are much, much bigger than electrons. A proton is more than 1,000 times as heavy as an electron!
Protons and electrons have an electrical charge. Protons have a charge of +1, while electrons have a charge of -1.
Protons and neutrons are found in the nucleus of an atom. Usually there are about as many protons as neutrons. For example, the nucleus of a normal oxygen atom has 8 protons and 8 neutrons.
Sometimes protons are found outside of atoms. Some of those protons can get moving very, very fast. Protons like that are a type of particle radiation.
Oxygen (O2) is a kind of gas. A lot of the air you breathe is oxygen. That's a good thing, since we need oxygen to stay alive! About 4/5ths of the air in Earth's atmosphere is nitrogen (N2). Almost all...more
Text for this level has not been written yet. Please see the "Intermediate" text for this page if you want to learn about this topic. To get to the "Intermediate" text, click on the blue "Intermediate"...more
Did you know that a lot of what happens in space physics has to do with the interaction of really tiny particles? These particles like protons and electrons are so tiny that you can't even see them with...more
One way scientists measure the size of something is by its mass. Mass is sort of like weight. Scientists can even measure very, very tiny things like atoms. One measure of the size of an atom is its "atomic...more
Every atom has a nucleus. The nucleus has protons and neutrons in it. Scientists have a special name for the number of protons in an atom. They call it the "atomic number". There are almost 100 different...more
Isotopes are different "versions" of an element. All atoms of an element have the same number of protons. All hydrogen atoms have one proton, all carbon atoms have 6 protons, and all uranium atoms have...more
Everything you see around you is made of tiny particles called atoms. Atoms are so small that you can’t see them but scientists have found out that there are many different types of atoms, and each type...more
Atomic Physics and Particle Physics
A Matter of Scale - interactive showing the sizes of things, from very tiny to huge - from NSF
