Thorium is element number 90, with the symbol Th. Its name comes from Thor, the god of thunder in Norse myth.
Atomic number 90232.0
ThThoriumトリウム (toriumu)
Symbol
Th
Atomic weight
232.0
Place in the table
Period 7 · Actinoids
Atomic weight from the Chemical Society of Japan, “Table of Standard Atomic Weights with Four Significant Figures (2026)”.
The god of thunder
Thorium was discovered in 1828 in the mineral thorite and named after Thor, the Norse god of thunder.
Where it sits on the table
The fifteen elements from actinium to lawrencium are called the actinoids. On the Room of the Elements table they are in the lower of the two rows set apart at the bottom.
Think about it
Q1What about the element does the thunder god’s name suit?
Q2Find elements named after Norse myth (vanadium, thorium).
Q3Which actinoids were found before 1900?
There is no single right answer. Talking it over with someone at home is a good way to learn.
Did you know? — Elements linked to Norse myth: vanadium (god of beauty) and thorium (god of thunder).