In the chemical reaction 2H2 + O2 -> 2H20, what is the mole ratio of oxygen to water. A) 8:1

B)1:2

D)2:1

C)4:1​

Which of the following statements is true? a. elements in the last period are radioactive. b. atomic weight is the same as atomic mass. c. elements in the same group have the same number of electron shells. d. atomic number equals the number of neutrons in the nucleus of an atom.

Stage in which a star’s outer layers have started to cool and grow outward?

Geothermal energy for industrial use is available almost anywhere. a.true b.false