whats the difference between the first periodic table ( mendeleev ) and how is it different from the on we use today ? just wondering
2007-03-18 10:07:09 · 2 answers · asked by lancasterangel03 2 in Science & Mathematics ➔ Chemistry
Mendeleev use atomic mass to put the elements in order, today we use atomic number.
Mendeleev group them into families by their reactivity and left blanks for undiscovered elements, today we have a better arrangement of families and no blanks left.
Today we use electron configuration to put the elements into block on the table. Mendeleev did not know about this.
2007-03-18 10:11:23 · answer #1 · answered by physandchemteach 7 · 0⤊ 0⤋
Not much. Some gaps have been filled in with elements not known in Mendeleev's time, including elements 43 and 61, which have no stable isotopes but show up in fission products. X-ray analysis, which gives a direct evaluation of the atomic number, has nicely confirmed Dmitri's analysis.
2007-03-18 10:13:01 · answer #2 · answered by Anonymous · 0⤊ 0⤋