How many moles of mgsio3 are in 199 g of the compound?

Which real-world scenarios below represent physical and chemical changes? -running a car -exploding fireworks -mixing water and powdered drink mix -combining oil and vinegar to make salad dressing -taking aspirin for a headache -diluting bleach with water-digesting dinner-spreading peanut butter on bread

Embryos of different species look very similar, which shows that the organisms share a ancestor.

Light waves can move through , but they travel fastest when they move through a(n) .