How many pairs of electrons are shared between two adjacent carbon atoms in a saturated hydrocarbon?

The formation of a solid, also known as a is an indication of a chemical change. precipitate particulate particle powder

If you chip a tooth, most likely you will go to the dentist to have the missing material filled in. currently the material used to fill in teeth is a polymer that is flexible when put in, yet is hardened to the strength of a tooth after irradiation with blue light at a wavelength of 461 nm. what is the energy in joules for a photon of light at this wavelength?

Consider the four elements above. which one of these elements will combine with oxygen in a 1: 1 ratio?