Answer:
The correct option is: <u>B. 366 torr</u>
Explanation:
Given: <u>On the ground</u>- Initial Volume: V₁ = 8.00 m³, Initial Atmospheric Pressure: P₁= 768 torr;
<u>At 4200 m height</u>- Final Volume: V₂ = 16.80 m³, Final Atmospheric Pressure: P₂ = ?
Amount of gas: n, and Temperature: T = constant
<u>According to the Boyle's Law</u>, for a given amount of gas at constant temperature: P₁ V₁ = P₂ V₂
⇒ P₂ = P₁ V₁ ÷ V₂
⇒ P₂ = [(768 torr) × (8.00 m³)] ÷ (16.80 m³)
⇒ P₂ = 365.71 torr ≈ 366 torr
<u>Therefore, the final air pressure at 4200 m height: P₂ = 366 torr.</u>
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:
<h3>
brainly.com/question/10257016</h3><h3 /><h3>#SPJ4</h3>
Explanation:
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The answer is 2.7gm/cm^3 . Density is mass divided by volume .