What are atoms held together by

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.

An atom of which element reacts with an atom of hydrogen to form a bond with the greatest degree of polarity ?

Draw a line graph showing the relationship between temperature in kelvin as a function of kinetic energy.