Chemistry, 13.12.2020 16:20, amyeaglin2003

1, The number of elements that have been discovered since 1871. 2. Four pairs of elements in the periodic table where the atomic masses are in the opposite order to the atomic numbers.
3. Ten elements that were named after planets and other heavenly bodies in the universe
4.Ten elements that were discovered and used by people as early as 2000 years ago.

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1, The number of elements that have been discovered since 1871. 2. Four pairs of elements in the pe...