Which is the limiting reactant in the following chemical reaction: 4nh3+5o2=4no+6h2o , if 4 grams of o2 is used and 2 grams of nh3 is used? a h2o b nh3 c no d o2

A100-watt light bulb radiates energy at a rate of 100 j/s. (the watt, a unit of power or energy over time, is defined as 1 j/s.) if all of the light emitted has a wavelength of 525 nm , how many photons are emitted per second?

Joan writes four numbers on the board in standard form, and then she writes their scientific notation

Aglow stick contains a glass vial with chemicals. when the glow stick is bent, the vial breaks and the chemicals react to produce a glow. a science student observes that a glow stick kept in the freezer glows for a longer duration than a glow stick kept at room temperature. what conclusion can be drawn based on the observation? be sure to note the outcome and test variables in the conclusion.