The answer would be choice B because the energy decreased by 20 J
Making repeated separations of the various substances in the pitchblende, Marie and Pierre used the Curie electrometer to identify the most radioactive fractions. They thus discovered that two fractions, one containing mostly bismuth and the other containing mostly barium, were strongly radioactive.
<h3>What was surprising about pitchblende?</h3>
Since it was no longer appropriate to call them “uranic rays,” Marie proposed a new name: “radioactivity.”
Even more surprising, Marie next found that a uranium ore called pitchblende contained two powerfully radioactive new elements: polonium, which she named for her native Poland, and radium.
<h3>Why is radium more radioactive than uranium?</h3>
It is 2.7 million times more radioactive than the same molar amount of natural uranium (mostly uranium-238), due to its proportionally shorter half-life.
Learn more about highly radioactive elements here:
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brainly.com/question/10257016</h3><h3 /><h3>#SPJ4</h3>
The term that is being described above is what we call IMMISCIBLE. This means when liquids are immiscible, it cannot be mixed in order to make a homogeneous mixture. When two liquids are mixed, these will eventually form layers. The answer to this is the first option. Hope this helps.
Sound Waves require a medium
Answer:
3.43 moles
Explanation:
To convert moles into grams you must take the number of grams and divide it by the atomic mass of the compound.
in this case, grams is 151 and N2O has an atomic mass of 44.013
so your equation would look like
151/44.013=3.430804535
your answer would be 3.43 moles
