Answer:
The Sun and the planets were born from a cloud of gas and dust called the solar nebula 4.6 billion years ago. The collapse of the solar nebula was most likely triggered by a shock wave from a nearby supernova explosion. The Sun formed in the center, with the planets surrounding it in a thin disk.
Explanation:
I’d say A. They are theoretical in the fact that they have not been observed directly, but have been confirmed to exist through experimentation.
Answer:
a.
△H=−72 kcal
The energy required for production of 1.6 g of glucose is [molecular mass of glucose is 180 gm]
b.
The iron(III) ions and chloride ions remain aqueous and are spectator ions in a reaction that produces solid barium sulfate.
Water can't cool at a single temperature. It must start at a higher temperature, and drop to a lower temperature in order to cool. Unless we know the other temperature, there is no way to calculate the amount of thermal energy released.
