Don't answer this you notifications well Lego step

Significant figures are digits read directly from the measuring instrument plus one more digit, which is __ by the observer.

What type of reaction fuels the processes seen here?

Which aqueous solution of ki freezes at the lowest temperature? 1) 1 mol of ki in 500. g of water 2) 2 mol of ki in 500. g of water 3) 1 mol of ki in 1000. g of water 4) 2 mol of ki in 1000. g of water