What is the product of 3.15 m and 2.006 m with the correct number of significant figures?

Six solutions are made, each with a y concentration of 1.0 μm and varying concentrations of ab as shown below. based on the concentrations, rank the solutions in decreasing order of reaction rate.

Calculate the amount of heat produced when 18000 coulombs of charge is transferred in one hour through a potential difference of 50v

I'm thinking it's 2 you are asked to explain the earth's magnetic field. which is the best reply? 1. the earth's magnetic south is similar to the north pole of a magnet. 2. the earth's core has a strong magnetic charge similar to the south pole of a magnet. 3. the earth's geomagnetic south is similar to the south pole of a magnet. 4. the earth's magnetic charge is not centered at either pole; it varies based on location.