How many moles of O2 will be produced if 4.5 x 1022 molecules of O2 are produced? Explain your answer.

Atrain travels 74 kilometers in 3 hours, and then 81 kilometers in 5 hours. what is its average speed?

Which element has the lowest electronegativity? calcium(ca) gallium(ga) selenium(se) bromine(br)

Consider the heating curve of h2o and line segments a, b, and c. several changes are taking place at a, b, and c. all but one would be an appropriate description as e move through segments a, b and then c.