After three half lives have passed, there would be only 12.5 percent of the original amount of a radioactive parent isotope that will remain. Half life is the time needed for a certain amount of a substance to be half its initial amount. It is a common term used in nuclear chemistry describing how fast radioactive substances undergo decay. One half life would correspond to only 50% would be left. Two half lives would be 25% only of the original value. Three half lives would be 12.5%. Four half lives would be 6.25% of the initial value. So on and so forth.
Answer:
Una cuenca es un área de tierra que drena todos los arroyos y la lluvia a una salida común, como la salida de un embalse, la boca de una bahía o cualquier punto a lo largo del canal de un arroyo.
Explanation:
Espero que esto ayude a marcar el MÁS CEREBRAL !!!
<span>A chemist adds 155.0ml of a 4.10 X 10^-5 mmol/L of a zinc oxalate (ZnC2O4)solution to a reaction flask. Calculate the mass in micrograms of zinc oxalate the chemist has added to the flask.
1mmol = 10^-3 mol
Therefore 4.10*10^-5mmol = 4.10*10^-8mol
molar mass ZnC2O4 = 65.39+(2*12.011)+(4*15.99) = 153.372g/mol
You have 4.10*10^-8 mol/litre =153.372 * 4.10*10^-8 = 6.29*10^-6 grams / litre (* see below)
But you have 155ml. Mass of ZnC2O4 = 155/1000*6.29*10^-6 g
Mass is = 9.75*10^-7 grams
1µg = 10^-6 g
You then have 9.75*10^-7/10^-6 = 0.975µg ZnC2O4
(*see below) at this point you could have said:
1µg = 10^-6 g therefore you have a solution of 6.29µg per litre,
155ml = 6.29*155/1000 = 0.975µg ZnC2O4</span>
A Calorie unit used in food is equal to the amount of energy necessary to raise the temperature of 1 kilogram of water by <u>1</u> degrees Celsius.
<h3>What is One Calorie ?</h3>
The amount of heat energy required to raise the temperature by 1 gram of water through 1°C is known as One Calorie.
1 Calorie = 4.18 J
Thus from the above conclusion we can say that A Calorie unit used in food is equal to the amount of energy necessary to raise the temperature of 1 kilogram of water by <u>1</u> degrees Celsius.
Learn more about the One calorie here: brainly.com/question/1061571
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Lovely song just asking is there a question so I don't get hate for not knowing rather there's a question or not
