Atoms are very small. They have a radius of around 1 × 10 10 metres. This symbol shows that chlorine has 35 particles in the nucleus (protons and neutrons), 17 of which are protons. It also tells us ...

Note: This video is designed to help the teacher better understand the lesson and is NOT intended to be shown to students. It includes observations and conclusions that students are meant to make on ...

No one really knows what happens inside an atom. But two competing groups of scientists think they've figured it out. And both are racing to prove that their own vision is correct. Here's what we know ...

This image depicts the radium atom’s pear-shaped nucleus of protons and neutrons in the center, surrounded by a cloud of electrons (yellow), and an electron (yellow ball with arrow) that has a ...

If you expanded an atom to the size of a baseball, what would it look like? And how would the inside look if you sliced it open? The nucleus is the atom’s central core and contains more than 99.9 ...

When two hydrogen atoms get close enough, the electron from each atom feels an attraction from the proton in the other atom's nucleus. This attraction pulls the atoms together. The electrons end up ...

For four years, James Chadwick was a prisoner of war in Germany. When World War I ended, he returned to his native England to rejoin the mentor of his undergraduate days, Ernest Rutherford. Now head ...

Scientists have developed a new method that can help them probe inside atom’s nucleus. Developed by researchers at MIT, the method uses the atom’s own electrons as “messengers” within a molecule to ...

There are 118 elements. Each element is unique by virtue of the different numbers of electrons, protons, and neutrons its atoms contain. Isotopes are atoms of a given element that vary only in the ...

Static electricity works because electrons are strongly attracted to protons, right? But, in atoms, electrons are right there, next to the protons in the nucleus. Why don’t the electrons zip directly ...