B. We are in the cenzoic era so what previously had happen to cause the life we live today was a huge mass extinction.... hope this helps!!
Answer:
0.093 mole of C₆H₁₂.
Explanation:
We'll begin by calculating the molar mass of C₆H₁₂. This can be obtained as follow:
Molar mass of C₆H₁₂ = (12×6) + (12×1)
= 72 + 12
= 84 g/mol
Finally, we shall determine the number of mole in 7.8 g of C₆H₁₂. This can be obtained as follow:
Molar mass of C₆H₁₂ = 84 g/mol
Mass of C₆H₁₂ = 7.8 g
Mole of C₆H₁₂ =?
Mole = mass / molar mass
Mole of C₆H₁₂ = 7.8 / 84
Mole of C₆H₁₂ = 0.093 mole
Thus, 7.8 g contains 0.093 mole of C₆H₁₂.
Answer: A) 3.21 g
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side.

We are given:
Mass of iron = 5.58 g
Mass of iron sulphide = 8.79 g
Mass of sulphur = x g
Total mass on reactant side = 5.58 + x
Total mass on product side = 8.79 g
Applying law of conservation of mass, we get:
Hence, the mass of reacting sulfur is 3.21 g.
Answer:
When you place the north pole of one magnet near the south pole of another magnet, they are attracted to one another.
Explanation:
The average speed is 0.28