A first-order reaction is 75.0% complete in 320. s. a. What are the first and second half-lives for this reaction? b. How long does it take for 90.0% completion?
Chem 1021 Elements, Compounds, and Mixtures Review: 1 Hg is called quicksilver and is mostly obtained by reduction from the mineral cinnabar. 2 Many window companies now us Kr to fill sealed panes in order to reduce energy waste, and the gas can also be used to detect leaks in industrial sealed containers. 3 Iron is one of the most plentiful elements. It comprises about 5.6% of the earth's crust and almost all of the earth's core. 4 Approximately 2/3 of the mass of the human body is Oxygen. 5 Calcium is essential for animal and plant nutrition. Calcium participates in many biochemical reactions, including building skeletal systems and moderating muscle action. Hg - mercury Kr - Krypton I