Video Transcript
An ion of copper has the nuclide
notation shown. Part (a) how many protons are there
in this ion of copper?
In this question, we are shown the
nuclide notation of a copper ion. Nuclide notation is a way to
represent the number of subatomic particles in an atom, ion, or isotope of an
element. In this problem, we will
specifically focus on an ion of the element copper. Recall that there are three
subatomic particles. Protons are positively charged
subatomic particles found in the nucleus. Neutrons are neutral, which means
that they do not have any charge. They are also found in the
nucleus. While protons and neutrons are
about the same size, electrons are quite a bit smaller. Electrons are negatively charged
subatomic particles found in the electron cloud outside of the nucleus.
Nuclide notation can be used to
represent the number of these subatomic particles in a specific ion in the following
way. E represents the chemical symbol of
the element. Let’s write out the nuclide
notation for the copper ion and interpret each part. We already know that the chemical
symbol Cu represents the element copper. The letter Z in nuclide notation
which appears in the bottom-left corner is the atomic number. This means that the atomic number
of the copper ion is 29. The atomic number is equal to the
number of protons in the nucleus. Therefore, there are 29 protons in
the nucleus of this ion of copper.
Part (b) how many neutrons are
there in this ion of copper?
Let’s continue to interpret the
nuclide notation of the copper ion. The letter A in nuclide notation,
which appears in the top-left corner, is the mass number. This means that in the copper ion,
the mass number is 65. The mass number is equal to the
number of protons in the nucleus plus the number of neutrons in the nucleus. Let’s substitute in the values for
the mass number and number of protons for the copper ion into this equation. We get 65 is equal to 29 plus the
number of neutrons. When we solve for the number of
neutrons, we get an answer of 36. There are 36 neutrons in this ion
of copper.
Part (c) how many electrons are
there in this ion of copper?
In the atom of an element, the
number of protons in the nucleus is equal to the number of electrons in the electron
cloud. Inside the nucleus of this generic
drawing of an atom, we see that there are two positively charged protons. Outside of the nucleus in the
electron cloud are two negatively charged electrons. When we add up the charge of
positive two from the protons and negative two from the electrons, we get an answer
of zero, which is why we say that atoms have no net charge or are neutral. On the other hand, ions of elements
do have a net charge. In nuclide notation, the charge on
the ion is shown in the upper-right corner. We can see that the charge of the
copper ion is two plus. Let’s use this simplified drawing
of a copper ion to analyze the number of subatomic particles inside.
In parts (a) and (b) of the
question, we already determined that the nucleus of the copper ion contains 29
protons and 36 neutrons. In an ion, the number of protons
and electrons are not equal. We’ll need to make use of the
following equation to determine the number of electrons in the ion. Let’s substitute in the charge and
the number of protons into this equation. After solving for the number of
electrons, we get an answer of 27. The electron cloud of the copper
ion contains 27 electrons. There are 27 electrons in this ion
of copper.
