PLZ help ASAP THANK YOU. :) i need all 3 and thank you again!

Fill in the coefficients that will balance the following reaction: a0cr2(so4)3 + a1agno3 -> a2cr(no3)3 + a3ag2so4

Which atom or ion is the largest? a. k b. k+ c. ca d. ca2+ e. li

Which process does not require the presence of a physical substance in order to transfer heat? air in the atmosphere is heated by the ground. this warm air then rises, and cooler air falls. this is an example of what type of process? how is conduction different from radiation?