Answer:
C. At some point, the land was covered in water.
Explanation:
In the diagram it shows the different fossil layers. In the bottom layers there are shells, but as you go up the fossils start changing. This shows that there used to be water there, but now it is land.
Answer:
BaSO₄
Explanation:
Let's assume we have 100 g of the compound. If that's the case we would have:
Now we <u>convert the masses of each element into moles</u>, using their <em>respective molar masses</em>:
- 58.8 g Ba ÷ 137.327 g/mol = 0.428 mol Ba
- 13.74 g S ÷ 32 g/mol = 0.429 mol S
- 27.43 g O ÷ 16 g/mol = 1.71 mol O
We <u>divide those moles by the lowest number among them</u>:
We can express those results as Ba₁S₁O₄, meaning the empirical formula is thus BaSO₄.
Don't understand the text, but water always freezes at 0°C as long as its water.
The answer to the question is D