CHEM 120 Unit 2 Exam Questions and Correct Answers Latest Update 2025 (Already Passed)

CHEM 120 Unit 2 Exam Questions and Correct Answers Latest Update 2025 (Already Passed) NH4^+ - Answers Ammonium NO2^- - Answers Nitrite NO3^- - Answers Nitrate C2H3O2^- - Answers Acetate CN^- - Answers Cyanide OH^- - Answers Hydroxide ClO^- - Answers Hypochlorite ClO2^- - Answers Chlorite ClO3^- - Answers Chlorate ClO4^- - Answers Perchlorate CrO4^2- - Answers Chromate CO3^2- - Answers Carbonate HCO3- - Answers Bicarbonate (hydrogen carbonate) SO3^2- - Answers Sulfite SO4^2- - Answers Sulfate HSO4^- - Answers Bisulfate (hydrogen sulfate) PO3^3- - Answers Phosphite PO4^3- - Answers Phosphate HPO4^2- - Answers Monohydrogen phosphate H2PO4^- - Answers Dihydrogen phosphate C2O4^2- - Answers Oxalate Cr2O7^2- - Answers Dichromate mon(o)- - Answers one di- - Answers two tri- - Answers three tetr(a)- - Answers four pent(a)- - Answers five hex(a)- - Answers six hept(a)- - Answers seven oct(a)- - Answers eight non(a)- - Answers nine dec(a)- - Answers ten What is the periodic law? - Answers When elements are arranged in order of increasing atomic number, there is a periodic repetition of their chemical and physical properties. What are columns (vertical) = groups = families of elements? - Answers Elements that have similar chemical properties are grouped in columns called groups or families. Elements with similar chemical properties appear at regular intervals, within the vertical columns call groups. What are rows (across, horizontal) = periods = series? - Answers Each row of elements on the periodic table is called a period. Each new horizontal row of the periodic table corresponds to the beginning of a new period because a new principle energy level is being filled with electrons. "-ate" Ions Mnemonic - Answers "Nick the Camel ate a Clam Supper in Phoenix" -nitrate -carbonate -chlorate -sulfate -phosphate Column 1 - Answers (1+) always, exception - sometimes H is (1-) but rarely. Column 2 - Answers (2+) always, no exception. Columns 3-10 - Answers Basically skipping Columns 3-10 because Transition Metals are complicated. Exceptions - Zinc & Cadmium are (2+) always; and silver is (1+) always. Column 13 - Answers Boron & Aluminum are always (3+), exception - the others are complicated. Column 14 - Answers Carbon & Silicon are always (4+) or (4-), exception - the others are complicated. Column 15 - Answers All are (3-), exception - the bottom (green) ones are complicated. Column 16 - Answers All are (2-), exception - the bottom (green) ones are complicated. Column 17 - Answers All are (1-). Column 18 - Answers Noble Gases do not react, so they don't form ions; therefore, they have no charges. What is atomic radius? - Answers 1) Use periodic table. 2) Half the distance between the nuclei of identical atoms that are bonded together. 3) As we go down a column on the periodic table, the atomic radius increases. 4) As we go across a period, from left to right, the atomic radius decreases. What is ionic radius? - Answers 1) Use ionic charges. 2) The distance from the nucleus to the outermost e- of an ion. 3) Cations are much smaller. 4) Anions are somewhat larger. 5) More positive = smaller. 6) More negative = larger. What are positive ions? - Answers 1) They are the smallest. 2) Smaller than neutral atoms and anions. 3) The higher the positive charge, the smaller an ion is. What are neutral atoms? - Answers 1) They are between positives and negatives. 2) Use the periodic table trend to compare one neutral atom to another neutral atom, not ions. What are negative ions? - Answers 1) They are the biggest. 2) Bigger than neutral atoms and cations. 3) The more negative they are , the bigger they are. What is electronegativity? - Answers A measure of the ability of an atom to attract the electrons when the atom is part of a compound. What is radioactivity? - Answers Radioactivity is the process by which atoms decay (or fall apart), and the larger the atom, the more likely it will fall apart.