Answer:
Explanation:The atomic number of sodium is 11. That is, the number of electrons in sodium is 11. Therefore, a sodium atom will have two electrons in the first shell, eight in the 2nd orbit, and an electron in the 3rd shell.
B. carbon because it's atomic number is 6
Answer: -40
Explanation: Percent error is calculated by subtracting the value you actually recieved from the literature value (175 in your case) SO your answer should be 135-175=-40.
Answer:
Molecular formula: S4K8O16 empirical formula: SK2O4
Explanation:
First we find the moles of each by first finding grams (using the percent) and then using stoichiometry to convert into moles:
Sulfur: 696 *.18 = 125.28grams S* 
Potassium: 696 *.4487 = 312.2952 *
= 7.99117 mole K
Oxygen: 696 * .367 = 255.432 *
= 15.9654 mole O
Then we divide each value by the atom with the smallest number of moles to find the mole ratio:
3.907/3.907= 1
7.99117 mole K/ 3.907= 2.043
15.9654 mole O/ 3.907= 4.08
The empirical formula is SK2O4
To find the molecular formula, we divide the mass given (696) by the mass of the empirical formula (174.22) to get 4. We then divide each atom by 4.
Molecular formula: S4K8O16