All the stable isotopes of boron, carbon, nitrogen, oxygen, and fluorine are shown in the accompanying chart (in red), along with their radioactive isotopes with t1>2 7 1 min (in blue). (b) Which radioactive isotopes are most likely to decay by beta emission? [Sections 21.2, 21.4, and 21.5]

Question

All the stable isotopes of boron, carbon, nitrogen, oxygen, and fluorine are shown in the accompanying chart (in red), along with their radioactive isotopes with t1>2 7 1 min (in blue). (b) Which radioactive isotopes are most likely to decay by beta emission? [Sections 21.2, 21.4, and 21.5]

Chart showing stable and radioactive isotopes of boron to fluorine by protons and neutrons.

Accepted Answer

Welcome back everyone. We're told that the accompanying chart in green displays all of the stable isotopes of boron carbon, nitrogen oxygen and flooring along with their radioactive isotopes with a half life greater than one minute in yellow is our nitrogen 15 most likely to undergo beta emission based on the chart. So considering all of our isotopes of boron, carbon, nitrogen oxygen and flooring, we want to recognize that boron, carbon, nitrogen, oxygen and flooring all have atomic masses represented by our symbol A. That are less than 200. And we can see that by looking at our periodic tables where we see our atomic mass. So we want to recall that when we have atoms that lie above or to the left of the band of stability, we would realize that we have too many and let's space that out. Too many protons in. And sorry, let's correct that too many neutrons in the isotope. And so the motive decay will either be beta decay or I'm sorry, this says, or neutron emission. So let's make sure this is all visible neutron emission. Now, looking at our diagram, given we recognize that in green, this is where we have all of our stable isotopes, meaning that this is going to be our band of stability. And according to the prompt, the boxes in yellow are the radioactive or we can consider more unstable isotopes here With half lives that are longer than one minute. And if we know that these green boxes represent our stable isotopes and our band of stability. And if we just outlined the fact that atoms that lie above or to the left of the band of stability, I'm sorry, this is band of stability. And this says lie here. If we know atoms that are lying to the left or above, the band of stability will have too many neutrons in their isotope and to mend this should undergo beta decay or neutron emission. And if we know that this is our band instability, we see that the only atom here is this atom with a half life of 5700 years, which corresponds to an atom with eight neutrons and six protons. So let's circle that eight neutrons this half life. And then six protons if we know our number of protons, six protons, that therefore tells us that we have an atomic number equal to six. And so on our periodic table, we see that the atomic number of six corresponds to our atom carbon. And we recall that our mass number is represented by our number of protons plus neutrons. So our eight or sorry, are eight neutrons Plus our six protons. Give us our mass number of 14, Which we will write in the left hand exponents there. So here we can confirm that only carbon 14 undergoes beta decay because it's the only isotope that is to the left of our band of stability. And so therefore for our final answer, we'll confirm that our nitrogen is unlikely to undergo beta emission. So for our final answer, our nitrogen 15, with atomic number seven here, Is unlikely to undergo beta emission, based on the fact that the only isotope that does undergo beta emission, because it lies to the left of the band instability is carbon 14, so it's highlighted in yellow is our final answer. I hope everything I reviewed was clear. If you have any questions, leave them down below and I'll see everyone in the next practice video.

All the stable isotopes of boron, carbon, nitrogen, oxygen, and fluorine are shown in the accompanying chart (in red), along with their radioactive isotopes with t1>2 7 1 min (in blue). (b) Which radioactive isotopes are most likely to decay by beta emission? [Sections 21.2, 21.4, and 21.5]

Verified Solution

Key Concepts

Isotopes

Beta Emission

Half-Life