Ionic compounds are composed of two ions: a positive and a negative ion. For neutral ionic compounds, these charges cancel out. For example, NaCl is a neutral atom which comes from a strong acid HCl and a strong base NaOH. Because they are both strong, the charges balance out and it comes out as neutral.
Answer:
Plates
Explanation:
The Earth's crust is broken up into sections called plates. Tectonic plates are on the mantle which allow them to move.
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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