An atom of calcium contains 20 protons. how many electrons does it have?

I am pretty sure there are 20 electrons, becuase there are the same amount of protons and electrons

Protons, neutrons and electrons. ... The number is used to arrange the elements in the periodic table, beginning with hydrogen, which has just one proton. Electrons are contained in shells around the nucleus. In a neutral atom the total number of electrons is always the same as the number of protons in the nucleus.

The Answer would be 20 electrons since protons and electrons are the same.

human didn't come from monkeys man i hate these stupid teachers

the correct answer is - d. china has a large and growing population.

the fact that china has a large (the biggest) population, and it is still growing, doesn't hinder the agriculture production in the country. in fact, it can for increased production in the agriculture, since there's more labor force, as well the sheer mass of people produces lots of scientists that come up with new inventions as to how to improve this sector. nice example is the inner mongolia region in china, in general dominated by the gobi desert, but few scientist came up with a nice idea as to how to make the region productive by using plants that are very resistant to droughts, so lots of people have been employed, and the region is becoming greener and greener each year, and the production of food in this region is also increasing.