What is the empirical formula of an unknown compound that contain 60.3% of magnesium and 39.7% of oxygen?

Which rate indicates the number of children that would be born per woman if she were to live to the end of her child bearing years

Two nails have identical sizes and shapes. in one nail, 20 percent of the domains are lined up. in the other nail, 80 percent of the domains are lined up. which has stronger magnetic force? first answer gets brainliest!

Akno3 solution containing 51 g of kno3 per 100.0 g of water is cooled from 40 ∘c to 0 ∘c. what will happen during cooling?