Answer:
Explanation:
There are some radioactive nuclides can be used to measure time on an archeological scale. One is the best example of this is radiocarbon dating. This process is based on the ratio of caebon-14 to carbon-12 in the atmosphere which is relatively constant.
The half time of C-14 5730 years
Carbon-14 is a radioactive nucleus. It has a half-life of 5730 years.
All living tissues like plants and animal absorbed carbon-12 along with carbon-14 with same ratio of caebon-14 to carbon-12 in the atmosphere.
Carbon-14 dating is based on the ratio of carbon-14 to carbon-12 in the atmosphere which is relatively constant
Answer:
Hygroscopic
Explanation:
An hygroscopic substance is one that absorbs moisture from the atmosphere and becomes wet. Their ability to remove water from air is less than that of deliquescent substances. Most of the solid hygroscopic substances forms pasty substances and not solutions like the deliquescent compounds.
Examples are sodium trioxonitrate(v), copper(ii) oxide e.t.c
Efflorescence compounds gives off their water of crystallization to the atmosphere.
Answer:
Lowering the temperature typically reduces the significance of the decrease in entropy. That makes the Gibbs Free energy of the reaction more negative. As a result, the reaction becomes more favorable overall.
Explanation:
In an addition reaction there's a decrease in the number of particles. Consider the hydrogenation of ethene as an example.
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When is added to (ethene) under heat and with the presence of a catalyst, (ethane) would be produced.
Note that on the left-hand side of the equation, there are two gaseous molecules. However, on the right-hand side there's only one gaseous molecule. That's a significant decrease in entropy. In other words, .
The equation for the change in Gibbs Free Energy for a particular reaction is:
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For a particular reaction, the more negative is, the more spontaneous ("favorable") the reaction would be.
Since typically for addition reactions, the "entropy term" of it would be positive. That's not very helpful if the reaction needs to be favorable.
(absolute temperature) is always nonnegative. However, lowering the temperature could help bring the value of