00:01
This question is, again, one of those very lengthy review questions of concepts that are presented in this chapter.
00:09
It is a series of statements that you are asked to identify as being true or false.
00:17
Although these questions can take a significant amount of time to answer as you thumb back and forth through the chapter, they serve as a very good review for the conceptual ideas presented in this chapter for an exam.
00:34
The first statement is the majority, greater than 50 % of the more than 300 naturally occurring isotopes are stable.
00:46
The answer to this statement is true.
00:49
It is true because if the naturally occurring isotopes, if the majority were not stable, then they would disappear and we would eventually end up with the more stable ones over time.
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Remember, the earth is and the solar system is 4 .8 billion years old, so they better be stable if they're naturally occurring.
01:12
That's the only way they would have stayed around for as long as they have.
01:17
Statement b, more artificial isotopes have been created in the laboratory than there are naturally occurring isotopes.
01:26
This is also true.
01:28
In your textbook, it mentions that there are many more artificial isotopes that have been created than are naturally occurring.
01:38
Around 1 ,000 artificial and 300 naturally occurring.
01:44
Statement c, all artificial isotopes are created in the lab.
01:50
All artificial isotopes created in the laboratory are radioactive.
01:56
Yes.
01:57
This is also true.
02:04
Statement d.
02:06
The term beta particle, beta emission, and beta ray, all refer to the same type of radiation.
02:14
Okay, so there's no answer to this in your textbook.
02:17
They do talk about beta particles and then interchangeably use the term beta emission, but there is nothing in your textbook about beta ray.
02:27
But i have also heard that term, although not very correct, because beta ray, it's not a ray, like a gamma ray that is nuclear magnetic radiation.
02:41
But nonetheless, i have heard that term beta ray.
02:44
So i would say this is true.
02:48
Statement e, when balancing the nuclear equation, the sum of the mass numbers and the sum of the atomic numbers on each side of the equation must be the same.
02:58
Yes, this is the criterion that must be followed in order to, to balance a nuclear equation.
03:07
So this is true.
03:10
Statement f, the symbol of a beta particle is superscript 0, subscript negative 1, and then the greek letter for beta.
03:22
Yes, this is true.
03:23
Sometimes it's also written as just an e here because a beta particle is just an electron.
03:30
Statement g, when a nucleus emits a beta particle, the new nucleus has the same mass number but an atomic number one unit higher.
03:43
Well, it is going to have the same mass number because the mass doesn't change when the beta particle leaves because it has no mass, but it will produce something with an atomic number one unit higher because it itself, the beta particle, has an atomic number of minus one.
04:00
This would be the only way the nuclear equation would be balanced.
04:04
So this statement is true.
04:06
Statement h.
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When iron 59 emits a beta particle, it's converted into cobalt, 59.
04:15
Well, let's see.
04:16
If we've got iron 59 emitting a beta particle, then something plus zero equals 59, so that would be 59, and then something minus 1 equals 26.
04:30
It would have to be 27.
04:32
And what is 27? 27 is cobalt, so this statement is true.
04:39
Statement i, when a nucleus emits a beta particle, it first captures an electron from outside the nucleus and then emits it.
04:49
Although there is such a phenomenon as electron capture, this is a different type of radioactive decay.
04:57
It is not what we call beta emission or the emission of a beta particle, so this is false.
05:04
Statement j.
05:06
For the purposes of determining atomic numbers in a nuclear equation, an electron is assumed to have a mass number of zero and an atomic number of minus one.
05:18
Yes, with the previous statements that we were looking at, this is exactly how we define a beta particle.
05:25
It has no mass, so a mass number of zero, and because of its one minus charge, has an atomic number of minus 1.
05:34
Statement k.
05:35
The symbol for an alpha particle is superscript 4, subscript 2, and then h .e.
05:41
Yes, this is how we define an alpha particle.
05:45
Sometimes we'll put a symbol alpha here instead of the he, but this is a very plausible and conventional way of defining an alpha particle, so this is true.
06:01
Statement l, when a nucleus emits an alpha particle, the nucleus has an atomic number two units higher and a mass number four units higher.
06:11
Well, this is the mass number and this is the atomic number.
06:18
So if an alpha particle is emitted, we are taking away four from the mass number, and we are taking away four from the atomic number.
06:28
So what is left will actually have a mass number four units less and an atomic number four units less.
06:37
So to state that they are both higher or greater than would be false.
06:41
They would be lower...