Answer:
4 orbits in the fourth period.
19 electrons in the atom from group 1 and fourth period.
Explanation:
Potassium has 19 electrons distributed in its 4 orbits
Cl-35, as the atomic mass of Chlorine (35.45) is closer to the number 35 than to the number 37. A higher abundance of CL-35 isotope would have caused the atomic number (which is an average of the values of all isotopes of a substances taking relative abundance into consideration) to decrease from 36, which would appear to be the average.
Answer: Lexington and Concord
Explanation: The British were trying to find weapons and could not find them.
Pure magnesium's formula would just be Mg because all elements except for 7 nonmetals are just left alone when they are by themselves in a formula. The 7 diatomic elements( means they have to have two of them without another element attached to it aka. a subscript two after it when it's by itself) are hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, and iodine. An easy way to remember the diatomic seven is that when looking at a periodic table if you trace over them from nitrogen over to fluorine and down to iodine all of those elements are diatomic + hydrogen.
And your unbalanced and balanced equations are correct.
(sorry I went on a tangent with the diatomic rules hopefully it will help you in the future though)