How many moles of calcium atoms do you have if you have 7.53 × 10²¹ atoms of calcium. (The mass of one mole of calcium is 40.08 g.)

Based on the law of conservation of energy, which statement is false? answer- energy is lost when machines dont work right

Idon't really understand this can you me and show your work.☺☺[ chemistry b] subject [ electron transfer in lonic bonds]grade( 12)

Asample of hydrated tin (ii) chloride (sncl2) has a mass of 4.90 g. when it is dehydrated, it has a mass of 4.10 g. which is the correct chemical formula for the hydrate? sncl2•2h2o          sncl2•4h2o          sncl2•6h2o