The periodic table has the elements on them. The first periodic table was first introduced to us in 1869 by a Russian scientist named Dmitri Mendeleev. Mendeleev studied chemistry at the University of St. Petersburg. Mendeleev’s table had many differences from the one we use today. His periodic table was in order by atomic mass.
Rare earth metals are a group of 17 that are found together on the periodic table. The whole rare earth metals are made only of metals. the group consists of yttrium and the 15 lanthanide elements. The first element in row 6 is lanthanum which is where the lanthanide group got its name. The word "rare” can make you think that the world is lacking these elements but the elements are in fact relatively abundant in the Earth's crust but in limited, insufficient amounts.
I have learned about which elements are liquids, solids, and gases. There are many kinds of elements. One type is alkali metals such as lithium, potassium, and sodium. There are also alkaline earth metals such as magnesium, radium, and calcium. There are transition metals like titanium, iron, cobalt, and zinc.
Mendeleev’s periodic table in the order of increasing atomic masses of the elements. Mendeleev also organized elements in columns depending on how they react. Moseley’s table is arranged in the order of increasing atomic numbers. 8. The element is cobalt and its electron configuration is 1s2 2s2 2p6 3s2 3p6 3d7 4s2.
Yashmakova, Alexandra 9/3 21 February, 2016 RESEARCH PARAGRAPHS ALUMINUM OXIDE Aluminum oxide is a chemical compound with the chemical formula Al2O3 which consists of oxygen and aluminium. It is found in the nature as the mineral corundum which is colourless and very hard substance used as an abrasive. Aluminum oxide is characterised with its colour, insolubility in water and its melting point which is 2030 oC. The boiling point of this compound is 2977oC. Its density is 3.97 g/cm³.
According to Chemicool.com, “An element is a substance consisting of atoms which all have the same number of protons, they are the simplest substances that cannot be broken down.” I will be focusing on an element called platinum. Platinum is considered to be one of the most valuable metals in the world. Platinum was 1st discovered in a tomb in an Egyptian tomb in 7th century BC, but this metal went under the radar until 1557, when an Italian scholar known as Julius Scaliger wrote about a metal located in South America that would not melt, which is now known as platinum. In 1735, Antonio Ulloa found platinum again, but he was captured by the royal navy and ended up in London. The royalty there was very interested in platinum, and by 1750 people were talking about platinum.
The periodic table that we know and use today is not the same periodic table we have always used. When the first periodic table was created in 1869, Russian chemist Dimitri Mendeleev had limited known elements making the table significantly different from the one we use today. Although both the Mendeleev periodic table and the modern periodic table look similar in shape, the organizational difference is what makes them unique. In Mendeleev’s time there were only 60 known elements. He knew there was need for a system of organization of the elements and thought his idea would be more useful than previous organizations.
Outlines the physical properties of the isotope The Physical properties of Plutonium 239 Colour: Plutonium is an actinide metal of silver colour, it forms an outer coating of dull grey appearance and begins to tarnish when exposed to oxygen. Melting Point: 639.5°C Boiling point: 3228°C. Density: 19.816 g/cm3 (at room temperature) Half-Life: 24110
If the atomic number is greater than 83 or if the ratio of neutrons to protons places it outside the zone of stability, it is unstable. Radioactive isotopes can be any of several type of the same chemical element with different masses. Their nuclei are
Calcium's melting point is 842°C, 1548°F, 1115 K and boiling point is 1484°C, 2703°F, 1757 K. Calcium is a silver-white soft metal, that reacts to halogens, water, and acid. This metal was first discovered by a man called Humphry Davy, in 1808 through the process of electrolysis while doing a mixture of lime (CaO) and mercuric oxide (HgO). Calcium is one of the most abundant elements on earth, forming over 3% of the earth's crust. It has 6 stable and several radioactive isotopes Calcium is the third most abundant metal in the earth’s crust, but