118 Elements and Their Symbols and Atomic Numbers: Definition, Symbol with Atomic Number
The periodic table is a well-organized chart that contains all the known elements in the universe. These elements are ...
BBC5 年
150 years of the periodic table: Test your knowledge
And generations of children have sung the words, "hydrogen and helium, lithium, beryllium..." in an attempt to memorise some of the 118 elements. This year, the periodic table of chemical elements ...