
rest from Consider the 2000 kg car shown below. The car coasts, from rest a height...
The element lanthanum has an atomic weight of 139 and consists of two stable isotopes lanthanum-138 and lanthanum- 139. The isotope lanthanum-138 has a mass of 138 amu and a percent natural abundance of 8.90X10-2 %. The isotope lanthanum-139 has a percent natural abundance of 99.9%. What is the mass of lanthanum-1392 A certain element consists of two stable isotopes. The first has a mass of 113 amu and a percent natural abundance of 4.28 %. The second has a...