Answer:
This is because it is a physical change not a chemical change.
The periodic table is useful tool for chemist since we can see what is the atomic and mass number for each atom.
Atomic number is equal to how many protons and electrons in it
Mass number is equal to protons + Neutrons.
Answer: UV Rays can't travel through glass, making it impossible to get a suntan because your body won't be able to respond if there is no UV getting to it.
Explanation: Glass absorbs and deflects a lot of UV light because the wavelengths aren't small enough to pass through and as a result, your body can't undergo its natural response of producing melanin, because the proteins activated by the UV damage won't be enacted.
To get the molarity you need to follow this equation
moles of solute
Molarity (M = -----------------------
Liters of solution
But before you apply that equation you need to find the moles of solute and the liters of solution. Follow this equation
Na2SO4 + BaCl2 = BaSO4 + 2 NaCl
Solution
Moles of BaSO4 = 5.28 g
---------------
233.43 g / mol
= 0.0226 moles
Moles of NaSO4 = 0.0226
0.0226 mole
Molarity = -----------------
0.250 L
= 0.0905 mol / L
So the answer is 0.0905 mol / L
