An atom of which element in the ground state contains electrons in the fourth principal energy level?

If 3.00 g of titanium metal is reacted with 6.00 g of chlorine gas, cl2, to form 7.7 g of titanium (iv) chloride in a combination reaction, what is the percent yield of the product?

Adrop of acetone (nail polish remover) has a mass of 35 mg and a density of 0.788 g/cm3. what is its volume in cubic centimeters?

The polymer used for the nonstick surface of cooking utensils is 24.0%c and 76%f by mass. what is the empirical formula of this polymer?