What was significant about the discovery of gallium?
It confirmed Mendeleev’s predictions and showed the usefulness of his table.
It was the last element to be discovered.
It was the first metal discovered.
It replaced aluminum on the periodic table.
The discovery of gallium was significant because it confirmed Mendeleev's predictions and showed the usefulness of his periodic table. Mendeleev had left gaps in his table for elements that had not yet been discovered, and gallium was one of these predicted elements. When gallium was discovered and found to have properties that matched Mendeleev's predictions, it provided strong evidence for the validity of the periodic table and its ability to predict the properties of unknown elements.
so is it a b or c
It is not b) - It was not the last element to be discovered.
It is c) - It was not the first metal discovered, but its discovery was significant in confirming Mendeleev's predictions and showing the usefulness of his periodic table.