The atomic mass of an element whose atoms consist of eight protons, nine neutrons, and eight electrons is
8
16
17
25

What substance has a mass of 9.5g and volume of 2.1cm^3

Amixture with the same composition throughout is!

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.