Determine the number of hydrogen atoms in 1.5 moles of water, h2o, molecules

Determine the wavelength of the light absorbed when an electron in a hydrogen atom makes a transition from an orbital in the n=3 level to an orbital in the n=7 level.

Which of the following elements would you expect to have the lowest ionization energy value? fluorine, lithium, neon, nitrogen

Skills of homo sapiens were found an excavation. the skulls were preserved because the bodies were frozen. so, these fossils are (blank) fossils.the image shows the evolution of skulls beginning 2 to 3 million years ago. based on the image, modern human skulls(blank) ape skulls.