Replace the question mark with a number
MATH PUZZLE: Can you replace the question mark with a number?Correct answers: 638
The first user who solved this task is Donya Sayah30.
#brainteasers #math #riddles
Periodic tableIn 1869, Dmitry Mendeleev published his first version of the periodic table of the elements. He was a Russian chemist who developed the periodic classification of the elements. In his final version of the periodic table (1871) he left gaps, foretelling that they would be filled by elements not then known and predicting the properties of three of those elements. |