Html viewer was selected to open .htm files and that would not handle mailto: and other links. This app reset that and then next time I opened the file it asked what app to use and I could select Browser (or Chrome). Perfect. At times, I want to use Chrome to open an .html file that I put on my tablet.
Neutrons have a mass of 1.675 Ã 10-24g, which is a little heavier than the proton. Neutrons are 1839 times heavier than electrons. Like all hadrons, neutrons are made of quarks. A neutron is made of two down quarks and one up quark. One up quark has a charge of +2/3, and the two down quarks each have a charge of -1/3.
The mass of a proton is approximately 1.6726 * 10^-24 g. Because the masses of particles in atoms are so small, scientists developed a new unit for them. The SI unit known as the atomic mass unit, abbreviated amu, is used to express the masses of subatomic particles. Scientists assign each proton a mass of 1 amu and symbol 'p.' All protons are identical, no matter from which kind of element they come. All the atoms of one element have the same number of protons.