| A | B |
|---|
| strong acids | • HCl, HBr, HI, HNO3, HClO3, HClO4, H2SO4 |
| strong bases | • LiOH, NaOH, KOH, Ca(OH)2, Ba(OH)2, Sr(OH)2 |
| kinetic-molecular theory of matter | • all matter consists of extremely tiny particles (atoms, molecules, ions), which are in constant motion |
| kinetic energy | • energy of motion of the particles that acts to overcome the forces of attraction between particles |
| heterogenous mixture | • not uniform • the properties in one region are different from those in another region • e.g blood, chicken noodle soup |
| homogenous mixture | • consists of two or more substances in the same phase • same properties in all regions • often called solutions • e.g. air, gasoline, unopened soft drink |
| elements | • substances that are composed of only one type of atom |
| atom | • the smallest particle of an element that retains the characteristic chemical properties of that element |
| chemical bonds | • an interaction between two or more atoms that holds them together by reducing the potential energy of their electrons |
| chemical compound | • matter that is composed of two or more kinds of atoms chemically combined in definite proportions • when elements become part of a compound, their original properties are replaced by the characteristic properties of the compound • some consist of ions some molecules |
| ions | • electrically charged atoms or groups of atoms |
| molecules | • the smallest discrete units that retain the composition and chemical characteristics of a compound |
| chemical formula | • represents the composition of any compound |
| Precision of a measurement | • Indicates how well several determinations of the same quantity agree o Expressed in terms of standard deviation |
| Accuracy | • The agreement of a measurement with the accepted value of quantity o Usually expressed in terms of percent error |
| mass number | • the sum of the number of protons and neutrons for an atom |
| • Isotope Percent abundance | =[number of atoms of a given isotope/total number of atoms of all isotopes of that element/x100%. |
| • Atomic weight | =[% abundance isotope 1/100][mass of isotope 1] + [% abundance isotope 2/100][mass of isotope 2]+... |
| Group 1A | • Alkali metals • Metals and solids at room temp • All very reactive so are only found in nature combined in compounds never as a free element |
| Group 2A | • Alkaline earth metals • metals occur naturally only in compounds |
| Allotropes | • Different forms of the same element having its own properties that exist in the same physical state under the same conditions of temperature and pressure • Aspect of nonmetals • E.g carbon exists as graphite, diamond |
| Group 7A | • Halogens • Nonmetals • All exist as diatomic molecules • Among most reactive of all elements • combine violently with alkali metals to from salts • react with other metals and with most nonmentals |
| Group 8A | • Least reactive elements • All gases • None abundant on earth or in earth’s atmosphere • Noble gases |
| • Molecular formula | o Describes the composition of molecules but it gives us no structural information |
| • Condensed formula | o Indicated how certain atoms are grouped together |
| • Structural Formula | o Gives us an even higher level of structural detail, showing how all of the atoms are attached within a molecule |
| • molecular compounds | o compounds that consist of discrete molecules at the articulate level |
| • ionic compounds | o consist of ions • atoms or groups of atoms that bear a positive or negative electric charge |
| columbs law | o Electrostatice force= (Q1(charge on first)Q2(charge on sencond)/distance between ions squared |
