Gallium is element number 31, a metal with the symbol Ga. Of all the elements Mendeleev predicted, it was the first to be found.
Atomic number 3169.72
GaGalliumガリウム (gariumu)
Symbol
Ga
Atomic weight
69.72
Place in the table
Period 4 · Group 13
Atomic weight from the Chemical Society of Japan, “Table of Standard Atomic Weights with Four Significant Figures (2026)”.
Named for France
In 1875, the French chemist Lecoq de Boisbaudran found a new element in an ore containing zinc. The symbol Ga comes from Gallia, the old Latin name for France.
A prediction that corrected a discovery
Mendeleev had called the element that would fill a gap in his table “eka-aluminium” and predicted its properties. Gallium was exactly that element.
Mendeleev then pointed out that the density Boisbaudran first reported was wrong. Boisbaudran repeated his experiment, found the error, and corrected the value himself.
Think about it
Q1How could someone who never did the experiment spot an error in its result?
Q2What do you think of Boisbaudran, who redid his experiment when an error was pointed out?
Q3Look for elements named after countries.
There is no single right answer. Talking it over with someone at home is a good way to learn.
Did you know? — Elements named after countries include gallium (France), germanium (Germany), polonium (Poland) and francium (France). Nihonium (Japan) belongs to this group too.