Mendeleev's Periodic table simplified the study of elements. As the arrangements of elements showing similar properties were classified into groups, it was very useful in studying and remembering the properties of a large number of elements in a systematic way.
Prediction of New Elements
Based on the positions in the periodic table, Mendeleev could predict the properties of some undiscovered elements. He left three blanks for elements that were not discovered at that time. He was able to predict the properties of these unknown elements more or less accurately. He named them eka-boron, eka-aluminium and eka-silicon. He named them so, as they were just below boron, aluminium and silicon in the respective sub-groups. Eka-boron was later named as...
scandium, eka-aluminium as gallium and eka-silicon as germanium.
scandium, eka-aluminium as gallium and eka-silicon as germanium.
A Comparative Study of the Properties of Elements Predicted and Later Discovered
| Property | Eka-boron | Scandium |
| Atomic weight | 44 | 43.79 |
| Oxide | Eb2O3 | Sc2O3 |
| Specific gravity | 3.5 | 3.864 |
| Sulphate | Eb2(SO4)3 | Sc2(SO4)3 |
| Property | Eka-aluminium | Gallium |
| Atomic weight | 68 | 69.9 |
| Specific gravity | 5.9 | 5.94 |
| Melting point | Low | 303.15 |
| Formula of oxide | Ea2O3 | Ga2O3 |
| Solubility in acid and alkali | Dissolves slowly in both acid and alkali | Dissolves slowly in both acid and alkali |
| Property | Eka-silicon | Germanium |
| Atomic weight | 72 | 72.32 |
| Specific gravity | 5.5 | 5.47 |
| Melting point | High | 958 |
| Valency | 4 | 4 |
| Reaction with acid and alkali | Slightly attacked by acids, resists attack by alkali | Dissolves neither by hydrochloric acid nor sodium hydroxide |
Correction of Atomic Masses
Mendeleev's periodic table helped in correcting the atomic masses of some of the elements, based on their positions in the periodic table. For example, atomic mass of beryllium was corrected from 13.5 to 9.0. Atomic masses of indium, gold and platinum were also corrected.
Mendeleev's Periodic Table
Period  | Group I | Group II | Group III | Group IV | Group V | Group VI | Group VII | Group VIII |
| 1 | H=1 | - | - | - | - | - | - | - |
| 2 | Li=7 | Be=9 | B=11 | C=12 | N=14 | O=16 | F=19 | - |
| 3 | Na= 23 | Mg= 24 | Al= 27.3 | Si=28 | P=31 | S=32 | Cl=35.5 | |
| 4 First series | K=39 | Ca=40 | Sc=45 | Ti=48 | V=51 | Cr=52 | Mn=55 | Fe=56 Co=58.9 Ni=58.7 |
| 4 second series | Cu =63 | Zn= 65 | Ga=70 | Ge= 73 | As=75 | Se=79 | Br=80 | - |
| 5 First series | Rb= 85 | Sr=87 | Y=89 | Zr=91 | Nb=93 | Mo=96 | Tc=99 | Ru=102 Rh=103 Pd=106 |
| 5 second series | Ag= 108 | Cd= 112 | In= 115 | Sn= 118 | Sb=122 | Te=128 | I=127 | - |
| 6 First series | Cs= 133 | Ba= 137 | La= 138 | Hf= 178 | Ta=181 | W=184 | - | Os=190 Ir=193 Pd=106 |
| 6 second series | Au= 197 | Hg= 200 | Ti= 204 | Pb= 207 | Bi=208 | - |
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