Some nickel ores contain nickel sulfide. in the first stage of extracting nickel from nickel sulfide the nickel sulfide is heated in air to form nickel oxide and nickel dioxide
write the balanced equestrian for this reaction

Compare and contrast physical changes with chemical changes.

The volume of helium in a blimp is 6.28 x 10^9 millimeters. the density of helium in the blimp is .1786 kilogram/meter^3. find the mass of the helium in the blimp.

An animal cell loses the ability to convert energy stored in food to energy that the cell can use. which of the cell's organelles has stopped working? a.the mitochondria b.the nucleus c.the vacuoles d.the endoplasmic reticulum