Why is it unlikely to find pure alkali metals in nature?
They have low reactivity.
They are highly reactive.
They are made in the laboratory.
They are so rare.
The correct answer is: They are highly reactive.
Alkali metals, such as lithium, sodium, and potassium, belong to Group 1 of the periodic table and are highly reactive due to their low ionization energies. This means they readily give away their outermost electron to form positive ions. As a result, they readily react with oxygen, water, and other elements in nature. Therefore, it is unlikely to find pure alkali metals in their elemental form in nature.
The discovery of what element showed the usefulness of Mendeleev’s periodic table ?
germanium
gallium
scandium
aluminum
The correct answer is: germanium.
The discovery of germanium in 1886 by Clemens Winkler demonstrated the usefulness of Dmitri Mendeleev's periodic table. Mendeleev had left gaps in his table for elements that were yet to be discovered, and the properties and predicted position of germanium matched those gaps. This discovery validated the predictive power of the periodic table and its ability to accurately organize elements based on their properties and atomic structure.
The correct answer is: They are highly reactive.
Alkali metals such as sodium, potassium, and lithium are highly reactive elements. They have a single electron in their outermost energy level, which they try to lose in chemical reactions to achieve a stable electron configuration. This high reactivity makes it unlikely to find these metals in their pure form in nature.
When alkali metals come into contact with water or air, they rapidly react and form compounds. These compounds can include salts and oxides, which are more stable than the pure metals. Therefore, in nature, alkali metals are typically found in combination with other elements rather than in their pure form.
Although alkali metals can be obtained by electrolysis or other methods in the laboratory, their high reactivity limits their usefulness and practicality for everyday applications.