what is the magnitude of the gravitational force acting on 79.5 kg student due to a 60kg student student sitting 2.25 m away in the hall

It really doesn't matter for any of the questions that you've listed.

Chromium  +  hydrogen sulfate  =  chromium(iii) sulfate  +  hydrogenso then it will be  a. cr + h2so4? cr2(so4)3 + h2 

Answer;

hot magma rises and pushes up toward the lithosphere, and as it cools it cycles back down toward the core to be heated again.

explanation; convection currents are the circular pathways taken by a fluid that enhances heat transfer by the process known as convection which occurs in fluids.convection currents transfer heat from one place to another by mass motion of a fluid. earth mantle is in a semi-liquid state and behaves like any other fluid, rising up from the bottom of the mantle after becoming hotter and less dense from heat of the earth's core, as the rock loses heat into the earth's crust it becomes cooler and more dense, then sinking back down to the core, then repeating the cycle.

Answer175 to 225 degreeswhite