Which of the following gases are typically used for colorful lighting when an electric current is applied?
a) hydrogen and helium
b) argon and krypton
c) fluorine and chlorine
d) oxygen and nitrogen

2. you__turn left on a red light if you are in the left-most lane of a one-way street, you're turning into the left-most lane of a one-way street, and no nearby sign prohibits the turn.

Which of these would be caused by a chemical change? a) the formation of lava. b) sedimantary rock layering over time. c) metamorphic rock forming from igneous. d) metamorphic rock eroding to form sedimentary rock.

How many moles of oxygen gas are produced from the decomposition of six moles of potassium chlorate