Metals and Halogens reactions Elements such as fluorine‚ chlorine‚ bromine‚ iodine‚ and astatine belong to Group 7‚ Halogens. At room temperature‚ fluorine is a yellow gas‚ chlorine is a pale green gas‚ bromine is a red liquid‚ and iodine is a purple solid. Astatine is a radioactive element‚ therefore it exists only in small amounts. All the halogens exist in diatomic molecules. They have high ionization energies and are the most electronegative elements. Their electron configuration ns2 np5 make
Premium Chlorine Sodium chloride Periodic table
The Atomic Mass of Metallo You may have noticed on the periodic table that the atomic mass of an element is usually not a whole number. That happens because of isotopes. An atom that is missing a neutron or has an extra neutron is called an isotope. They are still the same element; however‚ they are just a little different from every other atom of the same element. Most of the carbon atoms in the universe are Carbon-12‚ with 6 neutrons. A small percentage of carbon atoms are Carbon-13‚ with 7 neutrons
Free Chemical element Atom Carbon
TOEFL iBT™ Quick Prep Volume 1 Go anywhere from here. TOEFL iBT™ Quick Prep INTRODUCTION Introduction About the toeFL ibt™ test The TOEFL iBT test measures your ability to use and understand the English language as it is read‚ heard‚ spoken‚ and written in the university classroom. As the most accepted English-language test in the world‚ more than 7‚500 universities‚ agencies‚ and other institutions in more than 130 countries accept TOEFL scores as part of their admissions criteria
Premium Chemical element Periodic table Atomic number
Dear reader‚ my original name is In Greek‚ Phosphoros‚ which means bringer of light‚ but I prefer to be called by my English name Phosphorus‚ but for easier reasons you can call me P. I am pretty much at the beginning of the periodic table‚ thanks to my atomic number of 15. Wonder what’s an atomic number? It is basically the number of protons‚ which is my positive charge‚ that I contain at my nucleus. The nucleus does not only contain protons‚ but also neutrons‚ which will be important to know of
Premium Periodic table Chemical element Electron configuration
theory of evolution. Gregor Mendel soon came after‚ his work starting the study of genetics. Dimitri Mendeleev created a chart using John Dalton’s work consisting of elements and atoms‚ later on called the Periodic Table. Marie Curie and her husband‚ Pierre Curie found two missing elements of the table‚ radium and polonium. These discoveries caused more debates‚ opening a wider range of scientific answers to previously thought correct studies. The theories drove more scholars to observe things in a
Premium Marie Curie Chemical element Psychology
which is either an element‚ a compound or an alloy. Metals share some common properties like being typically hard and shiny‚ and that metals are good electrical and thermal conductors. They are generally malleable‚ fusible and ductile. In a periodic table of elements‚ there are six groups of metals and two of them are the most common. It is the Alkali Metals and the Alkaline Earth Metals. Alkali metals comprise the group 1 elements. They are similarly shiny‚ soft and highly reactive metals.
Premium Alkaline earth metal Metal Calcium
Before the discovery of gallium‚ its existence and properties were predicted by the Russian chemist Dmitri Mendeleev. He named the supposed element eka-aluminum as he predicted the element would be below aluminum in the periodic table of elements. In the year of 1875‚ the element Gallium was discovered by French chemist Paul E. Lecoq de Boisbaudran through a spectroscope in Paris. De Boisbaudran extracted gallium from a zinc blende ore from the Pyrenees and obtained .65 grams from 430 kilograms of
Free Periodic table Chemical element Chemistry
Surrounding the nucleus is a low density area containing negatively charged electrons that are equal to the number of protons within the nucleus. The number of protons within an atom determines the element that it composes. Every element within the Periodic table is defined by its atomic number (the number of protons in the atom). Elements with an atomic number between 1 and 92 are naturally occurring elements. Every element with an atomic number higher than 92 (having a nucleus with more than 92 protons)
Free Chemical element Atom Atomic number
Assignment 2 Question What is the role of engineering science in solving engineering problems? Engineering is about ensuring the health‚ happiness and safety of our planet ’s future. Engineers are at the centre of inventing creative solutions to address these challenges head-on. Now and in the future‚ engineers will play a vital role in finding solutions to many of the important issues facing us today‚ such as global warming‚ energy supplies‚ clean water‚ food shortages‚ transport‚ obesity‚ healthcare
Premium Engineering Chemistry Periodic table
My element is Lutetium and number 71 on the periodic table. It is the last of the lanthanide series and the rarest and most expensive of the series. Lutetium is always found with rare earth metals and it is very hard to separate from other rare elements. This is why it cost $10‚000 per kilogram. The lanthanide series is a series of metallic elements and is a part of the rare earth metals. Lutetium is silvery white and shiny. Of the rare earth metals it is the hardest and densest. Lutetium was
Premium Petroleum Chemical element Chemistry