The correct answer is B. a fossilized fish
That is because the scientist can use carbon dating to find the age of the fish, and that will tell the scientest the date of the layer of rock. :)
Red #40 is soluble in water while zinc oxide is not.
So the easiest way to separate them is as follows:
1- add water to the mixture until red #40 is dissolved in the water
2- filter to separate the zinc oxide
4- heat the solution of red #40 and water until water evaporates and red#40 remains.
Colligative properties are those substances that depend
on the number of substances in the solution, not in the identity of that
substance. The property changes the way that it does when the amount of solute
is increased because it enables the solute to be scattered more. For example,
the freezing point of salt water is lower than that of the pure water due to
the salt ions present in water.
Answer : The mass of arsenic present in 5.0 g of orpiment is, 1.5 grams.
Explanation : Given,
Mass of orpiment = 5.0 g
As we know that the molar mass of 
is, 246.02 g/mol and the molar mass of As is, 75 g/mol.
As per the question, we conclude that:
As, 246.02 g of contains mass of arsenic = 75 g
So, 5.0 g of contains mass of arsenic = 
Thus, the mass of arsenic present in 5.0 g of orpiment is, 1.5 grams.
This separation technique is a 4-step procedure. First, add H₂SO₄ to the solution. Because of common ion effect, BaSO₄ will not react, only Mg(OH)₂.
Mg(OH)₂ + H₂SO₄ → MgSO₄ + 2 H₂O
The aqueous solution will now contain MgSO₄ and BaSO₄. Unlike BaSO₄, MgSO₄ is soluble in water. So, you filter out the solution. You can set aside the BaSO₄ on the filter paper. To retrieve Mg(OH)₂, add NaOH.
MgSO₄ + 2 NaOH = Mg(OH)₂ + Na₂SO₄
Na₂SO₄ is soluble in water, while Mg(OH)₂ is not. Filter this solution again. The Mg(OH)₂ is retrieved in solid form on the filter paper.
