Convert 125.4 grams of MgSO4 to moles

Asingle atom of an element has 21 neutrons, 20 electrons, and 20 protons. which element is it? ok o z

Mike and mitchell decide to have a foot race. they mark off a stretch of 100 yards, and recruit cindy to work the stopwatch. after running the race and looking at the results, cindy declared that mitchell was the fastest. so how did the boys times compare?

If blood contains 150g of hemoglobin per liter of blood, how much hemoglobin would be contained in 10 ml of blood