1. How many moles of tin are needed to react with 3.5 moles of hydrogen fluoride?

When a scientific theory has been tested and proved by the scientific community, it becomes a law

In a heat engine of 1000 j of heat enters the system and the piston does 500 j of work what is the final internal energy of the system if the inital energy was 2000 j we have to do all of these down here 1)write the equation 2)list out your know variables 3)plug the numbers into the equations 4)solve 5)write your solution statemtn that includes inital energuy and final energuy added

Growing crops in places where major pests don't live using beneficial insects to eat harmful insects using a rat trap instead of a rodenticide developing drought-resistant tomato plants using beneficial insects or natural oils to repel pests planting a different crop every year to fake out the pests keeping food covered to deter ants and rodents developing bean plants with a resistance to fungus picking caterpillars off tomato plants cultivation practice biological control cultural control genetic resistance natural chemicals