A student heats a LaTeX: 2.5 g sample of calcium carbonate in a test tube. What mass of calcium oxide remains in the test tube when the reaction is complete? CaCO3(s) to CaO(s) + CO2(g)
Select one:
a) 1.4 g CaO
b)2.1 g CaO
c)2.5 g CaO
d)1.0 g CaO

Which of the following is a testable hypothesis? a. if i brush my teeth, i will get fewer cavities than if i don't brush my teeth. b. green toothpaste tastes better than blue toothpaste or red toothpaste. c. smart, careful, healthy people always brush their teeth. d. it's wrong to not brush your teeth before you have an important conversation with someone.

A50.0g sample of liquid water at 0.0 c ends up as ice at -20.0 c. how much energy is involved in this change?

Adeuteron, 21h, is the nucleus of a hydrogen isotope and consists of one proton and one neutron. the plasma of deuterons in a nuclear fusion reactor must be heated to about 3.02×108 k . what is the rms speed of the deuterons? express your answer using two significant figures.