Barium is element number 56, with the symbol Ba. Its name comes from the Greek word for “heavy.” Many people in Japan know it from the “barium” used in stomach X-ray exams.
Atomic number 56137.3
BaBariumバリウム (bariumu)
Symbol
Ba
Atomic weight
137.3
Place in the table
Period 6 · Group 2
Atomic weight from the Chemical Society of Japan, “Table of Standard Atomic Weights with Four Significant Figures (2026)”.
Named for “heavy”
The symbol Ba comes from the Greek barys, “heavy,” because barite, a mineral containing barium, is heavy. Barium was discovered in 1808.
Barium is in Group 2 of the periodic table, the same column as magnesium and calcium.
“Barium” for stomach X-rays
In a stomach X-ray exam, the patient drinks a medicine that expands the stomach and barium, a contrast agent, so that the inside lining of the stomach can be examined.
Japan’s curriculum guide lists 19 element symbols as basic examples for eighth-grade science: H, He, C, N, O, S, Cl, Na, Mg, Al, Si, K, Ca, Fe, Cu, Zn, Ag, Ba and Au. Barium is one of them.
Think about it
Q1Why do you think patients drink something special to show the shape of the stomach on an X-ray?
Q2Barium is named for being heavy. Find other elements named for their properties.
Q3How many of the 19 basic element symbols did you already know?
There is no single right answer. Talking it over with someone at home is a good way to learn.
Did you know? — Around 1887, the fireworks maker Kagiya Yahei, the eleventh of that name, succeeded in making colored “Western fire” fireworks using barium sulfide and other chemicals.