A glass object receives a positive charge by rubbing it with a silk cloth. In the rubbing process, have pro- tons been added to the object or have electrons been removed from it?

The electrons being removed from glass.

Explanation:

Given the glass object became positively charged by rubbing with a silk cloth.

The protons are present in the nucleus and are not free to move. While the electrons are free to move and roam between objects. So, when a glass is rubbed with a silk cloth, the electron leaves the glass object that will make a positive charge on the object.

h let me think

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.