Use the 1st order decay equation
<span><span>Cfinal</span>=<span>Cinitial</span><span>e<span>−kt</span></span></span>
by filling in and doing the math you will get:
<span> </span><span>Cfinal</span><span> = 1.11 grams Rn-222 after 23 days.
hope this helps
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Answer:
In cases where the water freezes, a release of energy occurs to the environment, therefore energy is lost, and it begins to "cool down".
The term cooling in chemical science today is not well seen since it is not considered that this exists, but would be replaced by the term "absence or loss of heat".
It is considered that a body cools when its temperature decreases, and if it continues to decrease as in the case of water, a point will reach the freezing point, which in this case that of water is 0 degrees Celsius, therefore when the cooling overcomes this thermal barrier the water solidifies "freezing"
Explanation:
In the case of pure water (H2O), the freezing point is 0 ° C. This means that, as long as it is at a temperature above 0ºC and below 100ºC (since that is its boiling point), the water will be in a liquid state.
The correct answer is cutting paper because it is an example of a physical change. A physical change is a change a change in the properties of matter that does not change the identity of the substance. On the other hand, chemical change is a change where the substance changes in identity after undergoing a process..
Answer:
2 and 4 so B) II and IV
Explanation:
I false ... stirring speeds up the rate of dissolution because it increases surface area . II is true , III false ... heating up speeds up the rates of dissolution , IV is true .
When frequency increases, wavelength increases
