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:
Explanation:
Researchers hope to gain knowledge about how the microbiome contributes to health and disease states.
Answer:
These properties are basically the inverse of each other.
Explanation:
- Electronegativity is the tendency of an atom to attract an electron and make it a part of its orbital.
Ionization enthalpy, is the energy required to remove an electron from an atom.
- More electronegative atoms have high ionization enthalpies If the energy required to remove an electron is less, i.e. the atom has more tendency to give electron, it would thus have less tendency to take electron.
- Values and tendency of electronegativity in the periodic table: In general, the electronegativity of a non‐metal is larger than that of metal. For the elements of one period the electronegativities increase from left to right across the periodic table. For the elements of one main group the electronegativities decrease from top to bottom across the periodic table. To the subgroup elements, there’s no regular rule.
- Values and tendency of ionization potential in the periodic table: The first ionization energy is the energy which is required when a gaseous atom/ion loses an electron to form a gaseous +1 valence ion. The energy which is required for a gaseous +1 valence ion to loose an electron to form a gaseous +2 valence ion, is called the second ionization energy of an element. In general, the second ionization energy is higher than the first ionization energy of an element.
The first ionization energies of the elements of one period increase from the left to the right across the periodic table. According to the elements of main group, the first ionization energies generally decreases from top to bottom across the periodic table.
<u>Answer:</u> 1.2 moles of carbon dioxide is produced for the given value of oxygen.
<u>Explanation:</u>
The chemical reaction for the combustion of acetylene follows the equation:
By stoichiometry of the reaction:
5 moles of oxygen produces 4 moles of carbon dioxide.
So, 1.5 moles of oxygen will produce = 
of carbon dioxide.
Hence, 1.2 moles of carbon dioxide is produced for the given value of oxygen.
The array will be created with the elements equal to null.
