Answer
a. The greatest number of elements was discovered in the period 1801-1850, with 28 elements discovered.
b. Mendeleev's table predicted the existence of elements with properties intermediate to those of known elements. Chemists used this information to target their experiments, which would lead to the discovery of several elements. Mendeleev's table allowed chemists to focus their efforts on elements with certain characteristics.
c. By 1900, 85 elements had been discovered. Considering the 113 elements included in this book, roughly 75 percent of these elements were discovered by 1900. As of today, 118 elements have been discovered (some are still being studied by the IUPAC to prove that they actually were produced, others are going through the naming process). This means that, more accurately, 72 percent of the elements were discovered by 1900.
Work Step by Step
a. The greatest number of elements was discovered in the period 1801-1850, with 28 elements discovered.
b. Mendeleev's table predicted the existence of elements with properties intermediate to those of known elements. Chemists used this information to target their experiments, which would lead to the discovery of several elements. Mendeleev's table allowed chemists to focus their efforts on elements with certain characteristics.
c. By 1900, 85 elements had been discovered. Considering the 113 elements included in this book, roughly 75 percent of these elements were discovered by 1900. As of today, 118 elements have been discovered (some are still being studied by the IUPAC to prove that they actually were produced, others are going through the naming process). This means that, more accurately, 72 percent of the elements were discovered by 1900.
