Test Ch. 7 Periodic Properties Newton Name Instructions: Circle the letter of the BEST answer(s). Some questions may have multiple answers; be sure to include all correct answers. Each correct question is worth two (2) points. 1) __________ is credited with developing the concept of atomic numbers. A) Lothar Meyer B) Ernest Rutherford C) Michael Faraday D) Dmitri Mendeleev E) Henry Moseley 2) Elements in the modern
Free Periodic table
Properties of Gallium Gallium is a chemical element that is located in Group 13 or the “Boron Group” on the periodic table of the elements. It has the chemical symbol Ga and has an atomic number of 31 meaning it has 31 protons and 31 electrons. The atomic mass of Gallium is 69 meaning it has 38 neutrons. Gallium is a transition metal and was discovered in 1875 by French Chemist Paul Emile Lecoq de Boisbaudran after the element was predicted by Dmitri Mendeleev who created the periodic table of the
Premium Oxygen Chemistry Hydrogen
The Periodic Properties of Atoms The Periodic Table: In the 1870’s‚ the Russian chemist Mendeleev developed the periodic table‚ based upon the relationship between the atomic weights of the elements and their chemical properties. As one ascends from lightest to heaviest elements‚ there is a periodic recurrence of chemical properties. For example‚ the elements with atomic numbers 2‚ 10‚ 18‚ 36‚ 54‚ and 86 all are chemically inert (the noble gases)‚ while those with atomic numbers one greater 3‚ 11
Premium Periodic table Electron configuration Atom
PERIODIC CLASSIFICATION OF ELEMENTS Introduction There are 115 elements that are known at present. Some elements have similar properties whereas some others have completely contrasting properties Scientists began to look for some pattern in the properties of these elements Dobereiner’s triads In 1817‚ Johann Wolfgang Dobereiner‚ a German chemist‚ classified elements into groups based on their properties. He kept all elements having similar properties in one group. Most of his groups had three
Premium Management Chemistry Oxygen
Periodic Classification of Elements Classification of Elements according to electron configuration ( type of subshell being filled) *valence electrons –outer electrons of atom which are those involved in chemical bonding ; accounts for similarities in chemical behavior among elemens within each of this groups * Representative elements/ Main Group elements * Group 1A-7A * Incompletely filled s/ p subshells * Display a wide range of physical and chemical properties
Premium Atom Electron configuration Periodic table
some of the ancient elements. Hennig Brand discovered phosphorus the first element. After the discovery of phosphorus‚ many more elements were discovered. Johann Dobereiner discovered that elements could be grouped in three sets and proposed the Law of Triads. Later‚ A.E.Beguyer de Chancourtois arranged the elements according to their atomic mass and created the first geometrical representation of the periodic table. John Newlands proposed the Law of Octaves which states the elements repeat the chemical
Premium Periodic table Atomic number
Contributors of the Periodic Table of Elements The First International Congress of Chemists took place in September 1860 in Karlsruhe‚ Germany to review scientific matters that there was little agreement to. Following this congress led to the development of the periodic table of elements. Top contributors to the periodic table included Staislao Cannizzaro‚ Dmitri Mendeleev‚ Henry Gwyn-Jeffreys Moseley‚ John William Strutt‚ William Ramsay‚ Friedrich Ernst Dorn‚ and Glenn Seaborg. Stanislao Cannizzaro
Free Periodic table Chemical element Atomic number
Mini Proposal Faculty of Education University of Malaya Topic of Research: Development and Evaluation of Humanism Elements in teaching and learning ‘Periodic Table of Elements’ among Form 4 students Prepared by: LIM PEI LEE (PGJ 110010) Post Graduate for Master in Education (Science Education) Semester 2‚ Session 2011/2012‚ Education Faculty‚ University of Malaya. Table of Contents |No. |Contents
Premium Periodic table Chemistry Chemical element
Janelle C. Gajardo IV-1 Mrs.Dimacutac December 5‚ 2011 Elements in the Periodic Table Trivia l Actinium (Ac) - radioactive element found in uranium ores‚ used in equilibrium with its decay products as a source of alpha rays.The name originates from the Greek word ’aktinos’ meaning ray or beam. l Argon (Ar) - they don’t often interact with other elements. This caused early mappers of the periodic table‚ such as Dmitri Mendeleev‚ to think of them as proud and noble. l Carbon (C) - can
Premium Chemical element Periodic table Dmitri Mendeleev
Scandium is an element on the periodic table. Its atomic number is 21. Its atomic symbol is Sc. It has a silvery white color. It is classified as a metallic. Its group on the periodic table is 3. Its atomic mass is 45. Its melting point is 1541 Celsius. Its boiling point is 2836 Celsius. Its atomic is 216 pm. These a really interesting element. Scandium was discovered in Scandinavia in 1878. It was discovered by a man named Nilson. There is two metals that scandium has that were only found in Scandinavia
Premium Atom Chemical element Electron