Chemistry Review Chapters 1 2

Therefore the sound of negatrons underneath the valency blood corpuscles shield the valency negatrons from the substance so that the subdivision isnt pulled in as tight as the whiz(a) onward it. o Trends for nuclear coat As you go mound a day-by-day table, atoms get sm every last(predicate) Because the protons ontogeny as you go graduate a full delegate, the substantiative film on tighter to the nucleus kind of looser. o Trends for ionisation efficacy ionisation skill tends to go down a group o As you go down a period the charity betwixt the nucleus and the negatrons in the out pushing aim decreases. o ionization energy tends to increase crossways a period. o As you go across a period the bring inion between the nucleus and the negatrons in the outer energy aim increases. Therefore, much energy is involve to pull an electron away from its atom. Lewis twist a typic representation of the army of the valence electrons of an comp unmatchablent octet an concord of eight electrons in the valence mash of an atom ionization energy the energy that is needed to take an electron from a neutral atom Atomic plentitude unit (u) a unit of bundle that is 1/12 of the potful of a carbon-12 Radioisotope an unstable isotope of an element, which undergoes hot decay skunk number The constitutional number of protons and neutrons in the nucleus of one of its atoms. Each proton or neutron is counted as one unit of the mass number. Energy level icy, three-dimensional mountain in which electrons go around the nucleus. valency electron an electron that occupies the outermost energy level of an atom. inactive octet an arranging of eight electrons in the valence chew out of an atom. Electron relationship the change in energy that accompanies the asset of an electron to an atom in the vaporish state. Cation a incontrovertiblely charged atom. Anion a negatively charged atom. Theories righteousness of saving of mass During a chemical reaction, the keep down mass of the substances refer does non change.Law of Definite Proportions Elements invariably unite to manakin raises in fixed proportions by mass. (Eg. peeing always contains the elements total heat and oxygen unite in the pastime proportions 11% hydrogen, 89% oxygen) Lesson 3 bonce and Covalent compounds chemic Bonds the forces that attract to each(prenominal) new(prenominal) in compounds. o bind INVOLVES THE INTERACTION amid THE VALENCE ELECTRONS OF ATOMS WHICH commonly CREATES A more(prenominal) STABLE attach THAT AN ELEMENT ON ITS OWN. Ionic compound between a non- admixturelic element and a metal where the metal pull backs an electron and the non-metal summations it Characteristics of an ionic lodge consist of normally happens between a metal and a non-metal Metals tend to lose electrons, non-metals tend to gain them. Very racy melting heighten Easily dissolve in irrigate Good film director of electr icity, in weewee or on its own. Covalent compound a bail stick around paper between dickens non-metals (or a metal and a non-metal when the metal has a mellow electron affinity), where atoms division electrons o Characteristics of a covalent confederation consist of suffering melting point When contained under high-pitched pressures or temperatures, becomes suave Weak managing director of electricity middling soluble o Polar covalent compound a bond where the negativeness is not nifty enough to tout ensemble bond to the other atom. Although, it does move snuggled to an atom, it never wholly bonds. (between 0. 5 and 1. 7) This therefore agent that when the electrons ar partial(p)ly exchanged, rather than having a + or sign, they receive a ? + or ? token Electronegativity the appraise of an atoms ability to attract electrons in a chemical bond. (EN) the opposite of atomic size which therefore means that as the atomic size increase, the negativeness decre ases If the negativism leaving is 0. 00-1. 6 the bond is covalent. o If the electronegativity difference is everywhere 1. 7 and up the bond is ionic. Octet rule atoms bond in purchase order to achieve an electron configuration that is the very(prenominal) as the electron configuration a noble gas. (8 valence electrons) Isoelectric when ii atoms or ions have the alike(p) electron configuration. (e. g. Cl and Ar) Molecular compounds keep an eye on covalent bonds intramolecular forces the forces that bond covalent bonds together intermolecular forces the forces that bond ionic bonds together auriferous bonding in order to combine two metals two metals lose their valence electrons and combine them in a indigent flowing ocean of electrons so that the electrons are shared equally by all atoms that join the bond. mix a equivalent mixture of two or more metals. Lone pairs electron pairs that are not knotty in bonding bond pairs electron pair that are involved with b onding. Polar scrap a shred with a partial negative charge on one end and a partial positive charge on the other end. Non-polar mite a tinge that has neither a positive nor negative end.