The half-life of a radioactive substance is 15 days. After 10 days a sample of the substance has been reduced to a mass of 4 mg. A. What was the inital mass (in mg) of the sample? B. Using your answer from above, after how many days will there only be 0. 3 mg of substance left?.
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Chemistry, 22.06.2019 15:00
20 pts âźď¸ an unmanned spacecraft travels to mars. mars has a lower strength of gravity than earth. where in the image is the spacecraftâs weight the greatest?
Answers: 1
Chemistry, 22.06.2019 15:30
Using the first volume and temperature reading on the table as v1 and t1, solve for the unknown values in the table below. remember to use the rules of significant figures when entering your numeric response.
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Chemistry, 22.06.2019 20:00
Phosphoric acid is a triprotic acid ( =6.9Ă10â3 , =6.2Ă10â8 , and =4.8Ă10â13 ). to find the ph of a buffer composed of h2poâ4(aq) and hpo2â4(aq) , which p value should be used in the hendersonâhasselbalch equation? p k a1 = 2.16 p k a2 = 7.21 p k a3 = 12.32 calculate the ph of a buffer solution obtained by dissolving 18.0 18.0 g of kh2po4(s) kh 2 po 4 ( s ) and 33.0 33.0 g of na2hpo4(s) na 2 hpo 4 ( s ) in water and then diluting to 1.00 l.
Answers: 3
Chemistry, 23.06.2019 01:00
What two factors can affect the properties of a hydrocarbon? a. the number of its carbon atoms and the number of single bonds b. the number of its carbon atoms and the arrangement of its atoms c. the arrangement of its atoms and the number of its double bonds
Answers: 1
The half-life of a radioactive substance is 15 days. After 10 days a sample of the substance has bee...
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