What is the amount of a solute (in mol) needed to make 0.250 L of an NaF solution with a concentration of 1.25 M?

Northern was a learned a fairly cold climate caused by see one from the atlantic ocean, but se was real and tends to be much warmer, sonia look good causes difference. a. cool wins cannot blow across a leg into the south mountains, b. prevent cold air from blowing over into south sea, c.the south is at much higher elevation, so it is closer to the sun, d. suppose early and has a sperience a drastic climate change in the past few years.

4al + 3o2 → 2al2o3 what does the "3" in front of o2 stand for? a) it indicates that there are 5 oxygen atoms after you add the coefficient and the subscript. b) it indicates that that there are are total of 6 oxygen atoms all bonded together as a single molecule. c) it indicates that there are 3 oxygen molecules chemically bonded to each other in the reaction. d) it indicates that there are 3 separate oxygen molecules in the reaction.

Can someone me with these problems? see the attachment, .