Synonyms that are in the dictionary are marked in green. Synonyms that are not in the dictionary are marked in red.
Antonyms that are in the dictionary are marked in green. Antonyms that are not in the dictionary are marked in red.
Because of it, the contents of the periodic table got drilled into their subconscious.
Radon is one of the elements in the periodic table you saw in high school, near the bottom of the chart.
Source: https://www.sltrib.com/news/2023/07/22/reality-check-how-much-danger-is/