Helium was originally discovered on the sun by a French astronomer named Pierre-Jules-Cesar Janssen. Janssen made his discovery when he observed a yellow line within the sun's spectrum in 1868 during a solar eclipse.
The English astronomer Sir Norman Lockyer identified that the yellow line discovered in the sun's spectrum was not produced by any element known to man at the time. Lockyer came to the conclusion that the new element was produced by the sun and named it helium. Helium was eventually found on Earth when Sir William Ramsey, a Scottish scientist, performed an experiment with clevite, a mineral that contains uranium.Learn More
A metallic bond forms when the valence electrons are not associated with a particular atom or ion. Instead, they exist as a "cloud" of electrons around the ion centers.Full Answer >
The total number of atoms in a molecule of sucrose is 45. This total is calculated by adding the number of atoms noted in its molecular formula, C12H22O11.Full Answer >
Three scientists independently discovered the element boron in 1808: Sir Humphrey Davy in London and Joseph Gay-Lussac and L. J. Thénard in Paris. Davy produced boron by combining potassium and boric acid in a chamber filled with hydrogen, while the French chemists combined boric acid with magnesium to similar effect.Full Answer >
Positively charged atomic particles are called protons. These particles, along with neutrons, exist in the nucleus of the atom. Protons and neutrons each have an atomic mass of one.Full Answer >