Is breathing into a BTB a physical or chemical change

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?

What are four significant sources of ghgs that come from wostem washington?

Mary is conducting an experiment on how pollution affects plant growth. how can she ensure that her data are reliable?