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3 years ago

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The half-life of an element is 200 years. If a 30 gram sample was originally deposited, how much is left after 200 years? Questi

on 2 options: 10 grams 15 grams 30 grams 60 grams
PLS HELP I NEED AN A

1 answer:

quester [9]3 years ago

7 0

The gram that will be left is 15grams

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What does the atomic number represent?

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C. The number of protons in the atoms nucleus.

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If one mole of a substance has a mass of 56.0 g, what is the mass of 11 nanomoles of the substance? Express your answer in nanog

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Answer:

616,0 ng is the right answer.

Explanation:

You should know that 1 mole = 1 .10^9 nanomoles

Get the rule of three.

1 .10^9 nanomoles ...................... 56.0 gr

11 nanomoles .....................

(11 x 56) / 1 .10^9 nanomoles = 6.16 x 10^-7 gr

Let's convert

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3 years ago

the average speeds of gas molecules in.cylinders A,b,c,d are 0.01 m/s, 0.005m/s ,0.1 m/s and 0.5 m/s, respectively .which cylind

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Decreasing the temperature of the reaction 3H2 + N2<----->2NH3. In this reaction, the product absorbs heat. WHICH WAY WILL

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The explanation is given below.

Explanation:

If the temperature of the reaction mixture is increased,then the equilibrium will shift to decrease the temperature.

If the temperature of the reaction mixture is decreased,then the equilibrium will shift to increase the temperature.

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$3H_{2}$ + $N_{2}$ ⇔ $2NH_{3}$

A decrease in the temperature favors the reaction that is exothermic (the forward reaction)because it produces energy.Therefore,if the temperature is decreased,the yield of the ammonia increases.

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3 years ago

Give the number of significant figures indicated 78

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2 significant figures

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