What is an atomic number ?

What is the percentage by mass of silicon (si) in iron aluminum silicate (fe3al2(sio4)3)?

What is the molar mass of potassium nitrate, kno3

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.