A) Calcium Dihydrogen Phosphate
B) Iron(II) Sulfate
C) Calcium Carbonate
D) Magnesium Oxide
E) Sodium Nitrite
F) Potassium iodide
Answer:
Potassium is an element, with the symbol K
Explanation:
An element is something that cannot be broken down any further, for example, calcium, its Ca.
A compound is when you bond two or more elements. Compounds can be broken down into its original elements, for example, H₂O, it contains two atoms of hydrogen and one atom of oxygen (both hydrogen and oxygen are elements).
The answer would be .5 mols because you take the total amount of grams, which is 20, and you had up the molar mass of sodium hydroxide, which would be 40. After you have this you would set this up as a stochiometry equation. With 1 mol on top you dived 20/40 to cancel out your grams. This leaves you with .5 mols
<span>The scientists discovered that when they organized elements in order of increasing atomic mass there is a pattern of repetition of properties (A). The periodic law was developed by Dmitri Mendeleev and Lothar Mayer in 1869. They worked independently of each other and both created a periodic table. They both arranged the items on the table by weight and both suggested that certain properties of the elements recur. The Mendeleev table is the most important table because the values for the atomic mass are the most accurate.</span>