Why is it better to press down at the end of the stapler then pressing at the middle to staple paper together

Explanation:

Force pushing down onto the staple dispensing mechanism (I have no idea what else to call it) is how it operates.  So the more you can push down onto that area the better, to a point of course but we'll assume you aren't trying to break it.  

You can think of this in two ways.  The force being closer to the part that needs the force is better, so if you move it further away there will be less force there, or you can look at the top of a stapler as a lever, with the hinged end as the pivot, so the further you are away from the pivot the less force you have to exert  to get the same amount of force pushing on the other end of the lever.  

Let me know if that doesn't quite make sense.  

  the grams     of oxygen gas   that can be produced     is 20.6   grams of o₂

calculation

2liclo₃ →   2 licl + 3 o₂

step 1:   find the moles of liclo₃

moles = mass÷ molar mass

from periodic table the molar mass of liclo₃ =6.9 +35.5   +(16 x3) =90.4 g/mol

moles=38.7 g÷90.4 g/mol=0.4281   moles

step 2:   use the   mole ratio   to calculate the moles of o2

from equation above, liclo₃: o₂   is 2: 3  

therefore the moles of   o₂=0.4281 moles x3/2 =0.6422   moles

step 3: find mass   of o₂

mass= moles x molar mass

from periodic table the   molar mass of   o₂ = 16 x2= 32 g/mol

mass=0.6422   moles   x   32 g/mol = 20.6 grams of o₂

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it