Select the statement that best summarizes the central idea of the article.

Electromagnets are useful in many situations because they can be turned on and off.
Motors change mechanical energy to electrical energy.
Electromagnets work whether or not electricity is passing through the wire.
Electromagnets are useful around the home but not in industry.

Read these sentences from the text. near the equator, the tropics receive the most rain on a consistent basis. as a result, the fresh water falling into the ocean decrease the salinity of the surface water in that region. [. .] . . as the salt content of sea water increases, so does its density. what can you infer about how rain affects the density of surface water near the equator?

How many grams of co(g) are there in 74.5 ml of the gas at 0.933 atm and 30o c?

For the reaction shown, calculate how many moles of no2 form when each of the following completely reacts. 2n2o5(g)→4no2(g)+o2(g) part a 1.0 mol n2o5 express your answer using two significant figures. nothing mol m o l request answer part b 5.4 mol n2o5 express your answer using two significant figures.