EOC WEEK REVIEW 2015

ENERGIZER What is the definition of a half life? Barium-122 has a half-life of 2 minutes. A fresh sample weighing 80 g was obtained. If it takes 10 minutes to set up an experiment using barium-122, how much barium-122 will be left when the experiment begins? Technetium-99m is used for brain scans. If a laboratory receives a shipment of 200 g of this isotope and after 24 hours only 12.5 g of this isotope remain, what is the half-life of technetium-99m? 6 hours The half-life of strontium-90 is 25 years. How much strontium-90 will remain after 100 years if the initial amount is 4.0 g? 0.25 grams Time:start2 min4 min6 min8 min10 min Mass:80 g40 g20 g10 g5 g2.5 g

TYPES OF BONDS Ionic: Between and metal and a nonmetal The metal gives electrons to the nonmetal Covalent: Between two nonmetals The atoms share electrons Sometimes one atom has a greater share of the electrons, this is considered a polar bond Metallic: Metals bond and share their electrons Alloys are formed

NAMING (EASY) IONIC COMPOUNDS What is the name of CaF 2 ? Since this compound does not involve a transition metal use the name of the metal and the non-metal but change the ending to “ide.” Calcium fluoride What is the chemical formula for Potassium Sulfide? Find the ion charges based on the periodic table, crisscross them down to determine how many atoms of each element are needed to form the compound. K +1 S -2 = K 2 S

NAMING (HARDER) IONIC COMPOUNDS What is the name of Fe 2 O 3 Crisscross the subscripts upwards. Place the charge of the metal as a roman numeral and end the nonmetal with “ide.” Fe 3+ O 2- = Iron III Oxide What is the chemical formula for Manganese II Sulfide Find the ion charges based on the roman numeral for the metal and the periodic table for the non-metal, crisscross them down to determine how many atoms of each element are needed to form the compound. Mn 2+ S 2- = Mn 2 S 2 = MnS

NAMING COVALENT COMPOUNDS What is the name of N 2 O 3 ? Use the subscripts as prefixes and place “ide” on the second non-metal. Dinitrogen trioxide What is the chemical formula for sulfur hexachloride? Use the prefixes as the subscripts, no prefix means there is only one atom of this element. The only time you do not use a prefix is when there is one atom of the first element in the name of the compound. SCl 6

ENERGIZER What is the electron configuration of cobalt? 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 7 Which element has the electron configuration 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 3 ? Arsenic

REMEMBER THE BLOCKS ON THE PERIODIC TABLE…

REMEMBER THE AUFBAU DIAGRAM…

ENERGIZER Use the diagram below to answer the following questions: What exists in a system that is at 1 atm and 150°? Does H 2 O always exist as a solid at 0 degrees Celsius? If not, how could this be explained?

BALANCING CHEMICAL EQUATIONS ___ NaCl + ___ F 2 → ___ NaF + ___ Cl 2