There are 195 countries in the world today. This total comprises 193 countries that are member states of the United Nations and 2 countries that are non-member observer states: the Holy See and the State of Palestine.
There are 50 US states.
The United States currently administers 16 territories as insular areas:
American Samoa.
Guam.
Northern Mariana Islands.
Puerto Rico.
U.S. Virgin Islands.
This information is from three sources. United Nations, Wikipedia, and United States and their satellite states aka countries.
CaO ( calcium oxide) is a basic oxide.
Answer:

Explanation:
An empirical formula shows the smallest whole-number ratio of the atoms in a compound.
So, we must calculate this ratio. Since we are given the amounts of the elements in moles, we can do this in just 2 steps.
<h3>1. Divide </h3>
The first step is division. We divide the amount of moles for both elements by the <u>smallest amount of moles</u>.
There are 0.300 moles of sulfur and 0.900 moles of oxygen. 0.300 is smaller, so we divide both amounts by 0.300
- Sulfur: 0.300/0.300= 1
- Oxygen: 0.900/0.300= 3
<h3>2. Write Empirical Formula</h3>
The next step is writing the formula. We use the numbers we just found as the subscripts. These numbers go after the element's symbol in the formula. Remember sulfur is S and there is 1 mole and oxygen is O and there are 3 moles.
This formula is technically correct, but we typically remove subscripts of 1 because no subscript implies 1 representative unit.
