I'm trying to make a Bohr model for Calcium and Potassium. How many electrons or whatever do i put?

Question

And it's 2 in the first shell thingy and 8 in all the ones after that.. right?

Answer 1

The total number of electrons of an element is the same as its atomic number. So basically, the number of protons in each element is equal to the number of electrons so that they cancel eachother out and the element gets a neutral charge.

Remember than in the 1st shell up to 2 electrons can be included. The 2nd shell can hold up to 8 electrons. The 3rd shell can hold up to 18 electrons and the 4th shell can hold up to 32 electrons. The formula to figure this out is 2(n^2) where n = the energy level.

So if you want to figure out how many electrons the 5th energy shell can hold, you plug in 5 in place of n: 2(5^2) = 2(25) = 50 electrons.

Now that you know that simply put the maximum number on electrons in each increasing energy level until you have used them all up.