Answer: 4.1 g of barium precipitated.
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number 
of particles.
To calculate the moles, we use the equation:
Given : moles of barium = 0.030
Molar mass of barium = 137 g/mol
x= 4.1 g
Thus there are 4.1 g of barium that precipitated.
Answer:6.022 x 10^23 molecules
Explanation: Since one mole of any chemical compound always contains 6.022 x 10^23 molecules, you can calculate the number of molecules of any substance if you know its mass and its chemical formula.
<span>Scientific notation is used to express large numbers in a way that is to use, readable, comparable to other numbers and convenient. It is especially useful for things that are very large and very small because it is very tedious to work with many zero's when completing complex math problems.</span>
Conductive when liquid - ions are charged particles, but ionic compounds can only conduct electricity if their ions are free to move. So ionic compounds do not conduct electricity when they are solid, but they do conduct electricity when they are dissolved in water or when they are melted.
