Answer:
The questions are incomplete
Explanation:
(b) This question is incomplete. However to calculate the number of moles of CuSO₄ present in the impure sample. The formula below can be used;
number of moles = mass of CuSO₄ present in the impure sample ÷ molar mass of CuSO₄
(c) This question is also incomplete. However, to calculate the mass percentage of CuSO₄ present in the impure sample of CuSO₄, the formula below can be used.
Mass percentage of CuSO₄ =
mass of CuSO₄ present in the impure sample/mass of impure CuSO₄ × 100
Thus, the mass of the impure sample must be measured also since the actual mass of the CuSO₄ present in the impure sample must have been measured before calculating the number of moles.
I believe the answer is D. The atmosphere, different layers of the atmosphere can help in different ways! The stratosphere helps protect us from the sun's rays; The Mesophere is what helps protect us from meteorites! It's so cold that they burn up in that area.
Earth is the right distance from the sun. It’s protected from harmful solar radiation by its magnetic field and the atmosphere keeps it warm. Earth contains the right chemical ingredients to sustain life such as H2O (water) and C (carbon)
