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.
Hydrogen has an atomic mass of 1.01 atomic mass units. An atomic mass unitis TINY. One gram is equal to about 600000000000000000000000 amu (or 6followed by 23 zeros). So, because the mass of hydrogen is close to 1 amu,1 gram of hydrogen contains about that same huge number of atoms.