Sign up for our free STEM online summer camps starting June 1st!View Summer Courses

### The element oxygen has three naturally occurring …

01:32
Manhattan College

Need more help? Fill out this quick form to get professional live tutoring.

Get live tutoring
Problem 93

The nucleus of 6 Li is a powerful absorber of neutrons. It exists in the naturally occurring metal to the extent of 7.5$\%$ . In the era of nuclear deterrence, large quantities of lithium were processed to remove 6 Li for use in hydrogen bomb production. The lithium metal remaining after removal of 6 Li was sold on the market. (a) What are the compositions of the nuclei of 6 Li and 7 Li? (b) The atomic masses of 6 Li and 7 Li are 6.015122 and 7.016004 amu, respectively. A sample of lithium depleted in the lighter isotope was found on analysis to contain 1.442$\%$ 6 Li. What is the average atomic weight of this sample of the metal?

a)
$6 \mathrm{L} \mathrm{i}=3$ protons, 3 neutrons
$7 \mathrm{Li}=3$ protons, 4 neutron.
b)
7.002 amu

## Discussion

You must be signed in to discuss.

## Video Transcript

guys we're doing Problem 93 a chapter two. The nucleus of a lithium six is a powerful job of neutrons. It exists a naturally occurring metal to the extent of 7.5%. In the era of nuclear deterrence, large quantities of lithium were a process to remove lithium six for use in hydrogen bomb production. The Lydia mentor may after removal of six lithium was sold on the market. What are the composition nuclei of looking him six and seven. So this is lithium six. This is Yeah, that should be a three. And this is let the M seven. So both lithium is They have to re protons and three electrons because that's their atomic number. The only thing now these air isotopes. So what difference is the number of nutrients? So find number of neutrons be subtracted back three atomic number by the mass number that gives us three neutrons here. And then we have seven minus three for neutrons here. Now, the average masses of of lithium six and seven are, uh are 6.15122 and 7.16 years ago. 4 a.m. U. Respectively, a sample of lithium depleting the lighter stuff was found. Analysis to contain 1.442% lithium. Six. Was he ever atomic weight of the sample? Let's get rid of this. And now So it's look the mass of our lithium. So let the M six 6.15 1 to 2, and then the percentage is 1.442 So we just convert that to a decimal and we add the atomic weight of lithium 7.16 euro 04 and then we do one minus this because that will give us the fraction that is, Let the M seven. That's gonna be zero point 68578 And then we plug everything into our calculator, and then we get her answer. So that's going to be seven point 002 a.m. You