A 40g sample of rock is studied in the lab. Geologists find that the sample is 3.75 billion years old. How much argon-40 is there in this sample?

What reaction is taking place? 02 + c3h8 = h20 + co2

Which process does not require the presence of a physical substance in order to transfer heat? air in the atmosphere is heated by the ground. this warm air then rises, and cooler air falls. this is an example of what type of process? how is conduction different from radiation?

Question 3(multiple choice worth 4 points) (04.04 lc) what does it mean when an element is reduced? it empties a valance shell, reducing its atomic radius. it gains electrons, reducing its overall charge. it increases electronegativity, reducing its ability to bond. it loses electrons, reducing its electron number.