When he left gaps because he needed to let some of the air in for he can get all of the piese together.
Mendeleev was able to predict the properties of the yet unknown element (Germanium) by the properties of the surrounding known elements on his periodic table of the elements. Predicting properties such as reactivity, density, atomic mass, etc., he knew where the undiscovered element would be placed.
He was able to work out the atomic mass of the missing elements, and so predict their properties. And when they were discovered, Mendeleev turned out to be right. For example, he predicted the properties of an undiscovered element that should fit below aluminium in his table. When this element, called gallium, was discovered in 1875, its properties were found to be close to Mendeleev's predictions. Two other predicted elements were later discovered, lending further credit to Mendeleev's table.
Mendelevium
Mendeleev placed his elements in order of increasing atomic mass. He placed elements with similar chemical properties in the same groups or families. He realized that there were some gaps in the table where an undiscovered element should go and made predictions about those elements before they were found.
Ununbiquadium is an undiscovered element with an atomic number of 1124.
Mendeleev used the term "eka-aluminum" to predict the properties of an undiscovered element that would have similar characteristics to aluminum. This was part of his periodic table where he left gaps for undiscovered elements. Eka-aluminum was later discovered and named gallium, confirming Mendeleev's periodic trends.
Mendeleev was able to predict the properties of the yet unknown element (Germanium) by the properties of the surrounding known elements on his periodic table of the elements. Predicting properties such as reactivity, density, atomic mass, etc., he knew where the undiscovered element would be placed.
He was able to work out the atomic mass of the missing elements, and so predict their properties. And when they were discovered, Mendeleev turned out to be right. For example, he predicted the properties of an undiscovered element that should fit below aluminium in his table. When this element, called gallium, was discovered in 1875, its properties were found to be close to Mendeleev's predictions. Two other predicted elements were later discovered, lending further credit to Mendeleev's table.
The element discovered by Mendeleev in 1871 was germanium. Mendeleev predicted the existence of this element and its properties before it was actually discovered.
Mendeleev used the increasing atomic mass of elements to arrange them in rows on the periodic table. This allowed for elements with similar properties to be grouped together and for the gaps to be left for undiscovered elements.
mendelevium
Dmitri Mendeleev organized the elements based on their atomic mass, grouping similar elements together and leaving gaps for undiscovered elements. This led to the creation of the periodic table, where elements with similar properties were placed in the same column.
The first element of the Mendeleev's periodic table is hydrogen (H).
mendeleev
Mendeleev
This element is mendelevium (element 101).
Mendelevium