An electron that is in the highest energy level of an atom and determines the atom's chemical properties is called a(n) paired electron. opposite-spin electron. valence electron. extra electron.

i had this on my unit activity, i can you if you are a plato student. are you a plato student?

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles