The element gallium has an atomic mass of 69.7 u and consists of two stable isotopes gallium-69 and gallium-71. the isotope gallium-69 has a mass of 68.9 u and a percent natural abundance of 60.4 %. the isotope gallium-71 has a percent natural abundance of 39.6 %. what is the mass of gallium-71

How many atoms are in 1.4 mil of phosphorus trifluoride (pf3)

Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? a. the balloons both rise. the cold balloon is larger than the warm balloon. b. the balloons rise at the same rate. both balloons are the same size. c. the warm balloon expands and rises. the cold balloon shrinks and sinks. d. the cold balloon expands and rises. the warm balloon shrinks and sinks.

Which of the following is not a good technique for managing used oil? a) have specific, labeled catch pans available for technicians who are collecting oil b) spills in your shop and any releases on pavement or outside should be poured down a drain c) do not use oil containers for antifreeze or other non-similar fluids d) be prepared for oil spills with the proper absorbents