Carbon monoxide (CO) reacts with hydrogen (H2) to form methane (CH4) and water (H2O). Upper C upper O (g) plus 3 upper H subscript 2 (g) double-headed arrow upper C upper H 4 (g) plus upper H subscript 2 upper O (g). The reaction is at equilibrium at 1,000 K. The equilibrium constant of the reaction is 3. 90. At equilibrium, the concentrations are as follows. [CO] = 0. 30 M [H2] = 0. 10 M [H2O] = 0. 020 M What is the equilibrium concentration of CH4 expressed in scientific notation? 1959 5. 9 x 10-2 0. 059 5. 9 x 102.

n2(g) + 3h2-> 2nh3(g)   this is the balanced equation

note the mole ratio between n2, h2 and nh3.   it is 1 : 3 : 2   this will be important.

moles n2 present = 28.0 g n2 x 1 mole n2/28 g = 1 mole n2 present

moles h2 present = 25.0 g h2 x 1 mole h2/2 g = 12.5 moles h2 present

based on mole ratio, n2 is limiting in this situation because there is more than enough h2 but not enough n2.

moles nh3 that can be produced = 1 mole n2 x 2 moles nh3/mole n2 = 2 moles nh3 can be produced

grams of nh3 that can be produced = 2 moles nh3 x 17 g/mole = 34 grams of nh3 can be produced

note:   the key to this problem is recognizing that n2 is limiting, and therefore limits how much nh3 can be produced.

im pretty sure its b

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.