In 1803AD, Osmium was discovered by Smithson Tennant when dissolving an impure sample of platinum in aqua regia, a mixture of hydrochloric and nitric acids. He was able to determine that the black powder left behind after dissolving the platinum was actually a mixture of two new elements, indium and osmium.
•Osmium is a bluish-white and shiny metal.
•Osmium is very hard and is brittle even at very high temperatures.
•Osmium has the lowast vapor pressure and the highest melting point among the platinum group of metals.
•Osmium's density is slightly more than iridium hence is credited as the heaviest element.
Answer:
These properties are basically the inverse of each other.
Explanation:
- Electronegativity is the tendency of an atom to attract an electron and make it a part of its orbital.
Ionization enthalpy, is the energy required to remove an electron from an atom.
- More electronegative atoms have high ionization enthalpies If the energy required to remove an electron is less, i.e. the atom has more tendency to give electron, it would thus have less tendency to take electron.
- Values and tendency of electronegativity in the periodic table: In general, the electronegativity of a non‐metal is larger than that of metal. For the elements of one period the electronegativities increase from left to right across the periodic table. For the elements of one main group the electronegativities decrease from top to bottom across the periodic table. To the subgroup elements, there’s no regular rule.
- Values and tendency of ionization potential in the periodic table: The first ionization energy is the energy which is required when a gaseous atom/ion loses an electron to form a gaseous +1 valence ion. The energy which is required for a gaseous +1 valence ion to loose an electron to form a gaseous +2 valence ion, is called the second ionization energy of an element. In general, the second ionization energy is higher than the first ionization energy of an element.
The first ionization energies of the elements of one period increase from the left to the right across the periodic table. According to the elements of main group, the first ionization energies generally decreases from top to bottom across the periodic table.
Answer: subduction and sea floor spreading
Explanation:
He knew that the continents today were once joined together by fossil records of plants and animals that were found to be on continents far removed from each other. He knew this also by corresponding land forms that matches up as well. What he couldn’t prove is how the land masses would have moved so far away from each other. Subduction and sea floor spreading move the tectonic plates that the continents sit on. That’s what he was missing.
