A student is trying to lift a metal ball off the floor. The student is unable to lift the ball after several tries. Which of the following forces is most likely opposing lifting the ball? possible 1. Electric force
2. Frictional force
3. Gravitational force
4. Magnetic force

In all living cells dna controls cellular activities by

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.

Upon decomposition, one sample of magnesium fluoride produced 1.65 kg of magnesium and 2.56 kg of fluorine. a second sample produced 1.32 kg of magnesium. part a how much fluorine (in grams) did the second sample produce?