Answer: Option (a) is the correct answer.
Explanation:
Enthalpy is defined as the total amount of heat present in a system.
When there is bond formation in a chemical reaction then it means energy is released. Hence, the reaction is exothermic in nature and 
< 0 or negative.
On the other hand, when breaking of bonds occurs then energy is absorbed by the system. Hence, the reaction is endothermic in nature and > 0 or positive.
Thus, in the given reaction 
, the state is changing from liquid to solid.
This means atoms are coming close to each other and hence, there is occurrence of bond formation. As a result, energy will be released to the surroundings.
Hence, we can conclude that H < 0 for the given reaction.
Answer:
Carbon dioxide is added to the atmosphere by human activities. When hydrocarbon fuels (i.e. wood, coal, natural gas, gasoline, and oil) are burned, carbon dioxide is released. During combustion or burning, carbon from fossil fuels combines with oxygen in the air to form carbon dioxide and water vapor.
Explanation:
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Answer:
C. Discrimination
Because at that time, slavery was very common and segregation was really typical too!
Red light has a wavelength of 700 nm, and a frequency of 4.3*1014 Hz. Visible light makes up just a small part of the full electromagnetic spectrum. Electromagnetic waves with shorter wavelengths and higher frequencies include ultraviolet light, X-rays, and gamma rays.
Answer:
a tough, light, flexible synthetic resin made by polymerizing ethylene, chiefly used for plastic bags, food containers, and other packaging.
Explanation:
