| A | B |
|---|
| Metals | are good conductors of heat and electricity, and all but on are solid at room temperature |
| malleable | something that can be hammered or rolled into sheets |
| ductile | something that can be drawn into wires |
| metallic bonding | In this, positively charged metallic ions are surrounded by a cloud of electrons |
| radioactive element | is one in which the nuecleus breaks down and gives off particles and energy |
| Transition elements | are those elements in groups 3 through 12 on the periodic table and ofte from colored compounds |
| Nonmetals | elements that usually are gases or brittle solids at room temperature. they are not shiny and do not conduct heat or electricity |
| diatomic molecule | consists of two atoms of the same element in a covalent bond |
| salt | if a halogen gains an electron from a metal, an ionic compound called this is formed like NaCl |
| sublimation | the process of a solid changing directly to a vapor without forming a liquid (dry ice) |
| Metalloids | can form ionic and covalend bonds with other elements and can have metallic and nonmetallic properties |
| Allotropes | are different forms of the same element, have different molecular structures |
| semiconductors | elements that conduct an electric current under certain conditions |
| transuranium elements | elements having more than 92 protons |
| chemical formula | tells what elements a compound contains and the exact number of the atoms of each element in a unit of that compound |
| chemical bond | the force that holds atoms together in a compound |
| ion | a charged particle |
| ionic bond | the force of attraction between the opposite charges of the ions in an ionic compound |
| covalent bond | the attraction that forms between atoms when they share electrons |
| molecule | a neutral particle that forms as a result of electron sharing |
| polar molecule | is one that has a slightly positive end and a slightly negative end although the overall molecule is neutral |
| nonpolar molecule | is one in which electrons are shared equally in bonds |
| binary compound | is one that is composed of two elements |
| oxidation number | tells you how many electons an atom has gained, lost, or shared to become stable |
| polyatomic ion | is a positively or negatively charged, covalently bonded group of atoms |
| hydrate | is a compound that has water chemically attached to its ions and written into its chemical formula |
| Why do metals conduct electricity? | because the outer level electrons are weakly held |
| mercury | not a solid at room temperature |
| ionic bonding in metals | metals can form an ionic bonds with nonmentals |
| Alkali metals | shiny, maleable and ductile; most reactive of metals |
| copper | has superior ability to conduct electricity |
| iron | main component of steel |
| chromium | used to harden steel |
| Elements in Group I are called | alkali metals |
| Elements in Group 2 are called | alkaline earth metals |
| Elements in Group 3 -12 are called | transition metals |
| Hydrogen | is highly reactive because it has one electron |
| Halogens | have 7 electrons in their outer levels |
| why are noble gases stable? | only exist as isolated atoms because their outer energy level are full |
| hydrogen makes | up 90% atoms in the universe. |
| alloptrope | ach of two or more different physical forms in which an element can exist. Graphite, charcoal, and diamond are all allotropes of carbon |
| Why make elements? | can gain an understanding of what holds the nucleus together |
| Outer energy levels | want to be full |
| combined elements | compound |
| chemical formulas | are symbol and number shorthand for the elments and their amounts (NaCl, H2O) |
