CLASSIFICATION of MATTER - VOCABULARY Atom the Smallest Particle of an Element That Retains Its Chemical Properties
CLASSIFICATION OF MATTER - VOCABULARY atom The smallest particle of an element that retains its chemical properties. A basic unit of matter that consists of a dense positively charged nucleus surrounded by a cloud of negatively charged electrons. molecule The smallest unit of a substance which can exist by itself and retain all its chemical properties. A group of atoms held together by chemical bonds. (The atoms in the molecule can identical as in H2 , O3 , P4 , and S8 or different as in H2O and NH3 .) matter Anything that occupies space and has mass. (Heat, light, radio waves are forms of energy.) substance (chemical substance, pure substance) A form of matter (material) that has constant chemical composition and definite properties (physical properties such as density, melting point, boiling point, electrical conductivity etc. as well as characteristic chemical properties). Substance made of a single type of microscopic particle (atom or molecule) and has a chemical formula. element (1) A chemical substance consisting of one type of atom. It is synonymous with the term elementary substance as opposed to compound. Copper metal that is made of individual atoms and oxygen gas that is made of diatomic molecules both exemplify this first concept. (2) A species of atoms; all atoms found in nature that have the same number of protons in the nucleus. Hydrogen and oxygen found chemically combined in water exemplify this second concept. compound (chemical compound) A substance whose molecules consists of unlike atoms (atoms of different elements) and whose constituents (chemically bonded elements) cannot be separated by physical means. mixture A form of matter (material) that has variable chemical composition and variable properties. It is a combination of two or more substances whose chemical species (atoms or molecules) retain their identities. The substances are combined without a chemical change and can be separated without a chemical change. homogeneous mixture (solution) A mixture whose components are thoroughly mixed at the molecular level. The largest particles present are atoms and/or molecules. (A homogeneous mixture looks uniform under the most powerful optical microscope. Its components will not settle down under gravity and will not be separated by filtration. Aqueous solutions is the most common example; they can be colored, but they are always clear meaning one can see through. Another common example are mixtures of gases.) heterogeneous mixture A mixture consisting of two or more homogeneous parts or regions (called phases). It either appears nonuniform or its nonuniform nature can be revealed by some optical techniques (microscopy, light scattering etc.) Matter (solid, liquid, gas)
Substances Physical Mixtures (constant composition) Change (variable composition)
Organic Elementary Chemical Compounds Homogeneous Compounds Heterogeneous Substances Change Mixtures Mixtures Inorganic (or Solutions) Compounds
Metals Nonmetals Metalloids Ionic Covalent Compounds Compounds
Representative Molecule Formula Unit Atom Atom Molecule Atom Formula Unit Particle
O2, O3, Cl2, SiO2(quartz), P4, S8 SiC NAMES AND SYMBOLS OF 50 MOST COMMON ELEMENTS
I. Ten elements whose symbols are the first letter of the name:
B Boron I Iodine S Sulfur C Carbon N Nitrogen U Uranium F Fluorine O Oxygen H Hydrogen P Phosphorus
II. Eighteen elements whose symbols are the first two letters of the name: Al Aluminum Ca Calcium Ne Neon Ar Argon Co Cobalt Ni Nickel Ba Barium He Helium Se Selenium Be Beryllium Kr Krypton Si Silicon Bi Bismuth Li Lithium Ti Titanium Br Bromine Mo Molybdenum Xe Xenon
III. Eleven elements whose symbols are made up of the first and the third letters of the name:
As Arsenic Cr Chromium Sr Strontium Cd Cadmium Mg Magnesium Pt Platinum (1st & 4th letter) Cs Cesium Mn Manganese Zn Zinc Cl Chlorine Rb Rubidium
IV. Eleven elements whose symbols are derived from ancient (often Latin) names: Sb Antimony Pb Lead Na Sodium (Stibium) (Plumbum) (Natrium) Cu Copper Hg Mercury Sn Tin (Cuprum) (Hydrargyrum) (Stannum) Au Gold K Potassium W Tungsten (Aurum) (Kalium) (Wolfram; German) Fe Iron Ag Silver (Ferrum) (Argentum) Group 1 17 18 I A VII A VIII A
1 2 13 14 15 16 II A III A IV A V A VI A
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3 3 4 5 6 7 8 9 10 11 12 III B IV B V B VI B VII B VIII B VIII B VIII B I B II B
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