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>
Answer: Cardiovascular System
Explanation:
This involves your heart, blood, veins, and arteries
Answer is: pressure of oxygen is 31,3 kPa.
The total pressure<span> of an ideal gas mixture is the sum of the </span>partial pressures<span> of the gases in the mixture.
p(mixture) = p(helium) + p(oxygen) + p(carbon dioxide).
p(oxygen) = p(mixture) - (p(helium) + p(carbon dioxide)).
p(oxygen) = 101,4 kPa - (68,7 kPa + 1,4 kPa).
p(oxygen) = 101,4 kPa - 70,1 kPa.
p(oxygen) = 31,3 kPa.
</span>
Answer:
Actual yield = 20.03g
Explanation:
% 
= 
Actual yield = % yield.(theoretical yield) / 100
Actual yield = 75.26.7/100
Actual yield = 20.025
This problem is very easy to answer. You simply have to look at the subscripts of each element of the compound.
1. For caffeine, which has a molecular formula of C₈H₁₀N₄O₂, it contains 8 atoms of Carbon, 10 atoms of Hydrogen, 4 atoms of Nitrogen and 2 atoms of Oxygen.
2. For Iron(III) Sulfate, which has a molecular formula of Fe₂(SO₄)₃, it contains 2 atoms of Iron, 3 atoms of Sulfur, and 12 atoms of Oxygen.
