Bonding in Polyatomic Ions and Compounds
Summary
TLDRThe video explains bonding in polyatomic ions and compounds containing them. Polyatomic ions are groups of covalently bonded atoms with a net charge. For example, nitrate (NO3-) consists of a nitrogen atom covalently bonded to three oxygens. In compounds like sodium nitrate, there are both ionic bonds between Na+ and NO3- and covalent bonds within the polyatomic ion. The video further explores how polyatomic ions gain or lose electrons to achieve stable bonds, resulting in their charge, using examples like hydroxide (OH-) and ammonium (NH4+).
Takeaways
- 🔋 Polyatomic ions are groups of atoms bonded together and carry a charge.
- ⚡ Nitrate (NO3 1-) is an example of a polyatomic ion, with nitrogen and oxygen atoms bonded covalently.
- 🧲 In compounds like sodium nitrate (NaNO3), there are two types of bonding: ionic bonding between ions and covalent bonding within the polyatomic ion.
- 🧪 Ionic bonds hold the sodium (Na+) and nitrate (NO3 1-) ions together due to opposite charges.
- 🧬 Covalent bonds hold atoms within polyatomic ions together, like the bonds between nitrogen and oxygen in nitrate.
- 🔍 Polyatomic ions have charges because of the gain or loss of electrons needed to form covalent bonds.
- 🧑🔬 Hydroxide (OH-) is a polyatomic ion where oxygen covalently bonds with hydrogen, gaining an extra electron and acquiring a negative charge.
- 🔑 The charge on polyatomic ions, like hydroxide, is due to the extra electron needed for bonding.
- 🔧 Ammonium (NH4 1+) is an example where nitrogen bonds with hydrogen and loses an electron, resulting in a positive charge.
- 🌟 Polyatomic ions form due to the need for atoms to either gain or lose electrons to satisfy their bonding needs, resulting in the charge seen on these ions.
Q & A
What is a polyatomic ion?
-A polyatomic ion is a group of atoms bonded together that collectively has a charge. These atoms are held together by covalent bonds, but the entire group functions as a single charged entity.
What type of bonds hold the atoms together in a polyatomic ion?
-The atoms within a polyatomic ion are held together by covalent bonds, which involve the sharing of electrons between atoms.
What type of bonding exists between polyatomic ions and other ions in a compound like sodium nitrate?
-In compounds like sodium nitrate, there are two types of bonding: ionic bonds between the sodium ion (Na+) and the nitrate ion (NO3−), and covalent bonds holding the atoms together within the nitrate ion.
Why do polyatomic ions have a charge?
-Polyatomic ions have a charge because during covalent bonding, the group of atoms either gains or loses electrons to achieve stability. This imbalance in electron count results in either a positive or negative charge.
How does the polyatomic ion nitrate (NO3−) get its charge?
-Nitrate (NO3−) has a charge of 1− because, during bonding, the atoms in the ion collectively gain one extra electron to achieve stable electron configurations, giving the ion an overall negative charge.
What happens when an oxygen atom bonds with a hydrogen atom to form hydroxide (OH−)?
-In the formation of hydroxide (OH−), the oxygen atom shares electrons with the hydrogen atom to form a covalent bond. However, oxygen needs one more electron to fill its valence shell, so it gains an additional electron, resulting in the hydroxide ion's negative charge.
What is the difference between ionic and covalent bonds in polyatomic ions?
-Covalent bonds occur within the polyatomic ion, holding the atoms together by sharing electrons. Ionic bonds occur between the polyatomic ion (which has a charge) and other oppositely charged ions in a compound, where opposite charges attract.
Why does the ammonium ion (NH4+) have a positive charge?
-The ammonium ion (NH4+) has a positive charge because during bonding, nitrogen and the four hydrogens share electrons, but they collectively have one extra electron, which they lose. Losing this electron gives the ion a positive charge.
What is the structure of the nitrate ion (NO3−) in terms of bonding?
-In the nitrate ion (NO3−), nitrogen is covalently bonded to three oxygen atoms. The ion as a whole has gained an extra electron, which gives it a 1− charge.
How do polyatomic ions like hydroxide (OH−) and ammonium (NH4+) gain or lose electrons?
-Polyatomic ions either gain or lose electrons based on the electron requirements of the atoms involved. If the atoms in the ion need additional electrons to achieve stable configurations, they gain electrons (like hydroxide, OH−). If they have excess electrons, they lose them (like ammonium, NH4+).
Outlines
🔬 Understanding Polyatomic Ions and Their Bonding
This paragraph introduces polyatomic ions, which are groups of atoms bonded together that carry a charge. Using nitrate (NO3-) as an example, the explanation highlights how the atoms in a polyatomic ion are held together by covalent bonds. The nitrogen and oxygen atoms form a 'clump' through covalent bonding, but the overall structure has a charge, which is why polyatomic ions behave the way they do. The sodium nitrate (NaNO3) example illustrates how compounds with polyatomic ions have both ionic and covalent bonding—ionic bonding between Na+ and NO3-, and covalent bonding within the NO3- ion.
⚛️ Why Polyatomic Ions Have a Charge
This paragraph explores the reason polyatomic ions carry a charge. It explains how covalent bonding and valence electrons are key factors. Using an oxygen-hydrogen example, it shows that sometimes atoms in a polyatomic ion don’t have enough electrons to satisfy their bonding needs, leading them to 'steal' electrons from the environment. When this happens, the entire polyatomic ion acquires a charge. In this case, by gaining an electron, the molecule (hydroxide, OH-) becomes negatively charged. The explanation is supported by using electron dot diagrams and Lewis structures to visualize this process.
🧪 The Role of Extra Electrons in Polyatomic Ions
This section provides a deeper example of how polyatomic ions either gain or lose electrons to maintain bonding stability. Using a nitrogen and hydrogen (NH4+) example, it explains how atoms that don’t need extra electrons will 'throw away' the excess, which results in a positive charge for the polyatomic ion. This is how the ammonium ion (NH4+) gets its 1+ charge. By walking through the math of valence electrons and electron distribution, the paragraph reinforces the concept that polyatomic ions gain or lose electrons to satisfy covalent bonding requirements.
Mindmap
Keywords
💡Polyatomic ion
💡Covalent bond
💡Ionic bond
💡Nitrate (NO3−)
💡Lewis structure
💡Valence electrons
💡Electron dot diagram
💡Ammonium (NH4+)
💡Charge
💡Sodium nitrate (NaNO3)
Highlights
Polyatomic ions are clusters of atoms held together by covalent bonds and have an overall charge.
Nitrate (NO3 1-) consists of one nitrogen atom and three oxygen atoms, held together by covalent bonds.
In sodium nitrate (NaNO3), both ionic and covalent bonds exist: ionic bonds between Na+ and NO3-, and covalent bonds within the NO3-.
Polyatomic ions like NO3- have both ionic and covalent bonds in the compound.
The charge on polyatomic ions is due to gaining or losing electrons to satisfy the octet rule in covalent bonding.
In hydroxide (OH-), oxygen and hydrogen atoms are covalently bonded, but the ion has an overall negative charge due to gaining one electron.
Polyatomic ions gain or lose electrons to balance their charge during covalent bonding.
In hydroxide (OH-), the additional electron gives it a -1 charge because oxygen needs one more electron to complete its valence shell.
In ammonium (NH4+), nitrogen is covalently bonded to four hydrogen atoms, but the ion has a positive charge due to losing one electron.
Ammonium (NH4+) has a +1 charge because the group of atoms loses an electron, making the nitrogen and hydrogen atoms 'happy' with their electron configuration.
Covalent bonds in polyatomic ions are responsible for holding the atoms together within the ion.
Ionic compounds with polyatomic ions, like NaNO3, involve both ionic bonds (between ions) and covalent bonds (within polyatomic ions).
The charge of polyatomic ions arises from the need to satisfy the atoms' electron configurations by gaining or losing electrons.
In ammonium (NH4+), nitrogen and hydrogen share electrons via covalent bonds, but the ion loses an electron, resulting in a positive charge.
Polyatomic ions can have either positive or negative charges based on whether they gain or lose electrons during bonding.
Transcripts
let's talk about bonding in polyatomic
ions and compounds that have polyatomic
ions in them so a whole bunch of
polyatomic ions this is just a small
list of some of them but they all share
one thing in common and that's that they
all are a bunch of atoms connected
together in a clump and that Clump then
has a charge okay that's what a
polyatomic ion
is let's take nitrate here NO3 1 minus
and we can draw the atoms in nitrate
like this one nitrogen and three oxygen
and this whole thing is surrounded by
brackets because it has a charge of 1
minus so nitrogen and those these three
oxygens they're a clump together okay
but what's holding the oxygens together
with the nitrogen right what's the glue
that connects these atoms together it is
actually Cove valent bonds that are
attaching the Oxygen's uh together with
the nitrogen so there is a coent bond
here a calent bond here and a calent
bond here keeping this clump of atoms
together so this is a little bit tricky
because it means that in a compound like
sodium
nitrate there are two types of bonding
going on okay there's ionic bonding
because opposite charges are attracting
okay because na can take a charge of 1
plus and NO3 as you can see right from
the list here has a charge of 1 minus
okay so the na and the NO3 are stuck
together because of ionic bonds here let
me show you what I
mean so here's the na+ and here's the
NO3 1 minus and these guys want to stick
together because they have opposite
charges so it's an ionic bond here
that's holding this whole Clump together
with this ion na+ here okay ionic bond
that's what I'm referring to here is the
attraction between these two things so
they're ionic bonds holding the positive
thing together with a negative thing but
then there are Cove valent bonds that
are holding all of the atoms together in
this clump of atoms that's nitrate okay
so uh an ionic compound with polyatomic
ions in it has both ionic bonds and
calent bonds okay now I want to address
another
question I want to explain
why polyatomic ions have a charge okay
now this has to do with coent bonding Le
structures electron dot diagrams and
some similar things veence electrons for
example if you don't know a lot about
these already no big deal you can turn
the video off and maybe you can watch it
later when you do understand these
things but if you already have a
background and this kind of stuff you
might be interested in how these clumps
of atoms actually get a charge in the
first place okay so as I
said it's all about coent bonding for
holding the atoms together in these
polyatomic compounds I mean for for
holding them together in these
polyatomic clumps okay so let's take an
example and see how the calent bonding
holding them together causes them to
have a
charge let's say that an oxygen atom
wants to come together with one hydrogen
atom I want to look at how the calent
bonding is going to work so I'm going to
want to draw a leis structure okay so in
order to draw a Luis structure I want to
find out how many veence electrons there
are in both of the atoms that I'm
working
with hydrogen is in this First Column
here so it has one veence electron to
find out how many valence electrons
oxygen has I can count 1 two 3 4 5 6 so
oxygen has six valence
now when I'm drawing the Lewis structure
I add these two up so I have seven total
veence electrons that oxygen and
hydrogen can share together okay so
here's the first step I'm going to take
oxygen and I'm going to draw it next to
hydrogen and now I'm going to take my
seven electrons here they are and I'm
going to arrange them around oxygen and
hydrogen so that both atoms have full
valence
shells oxygen wants to have eight
electrons but hydrogen is happy with
only two veence electrons in its outer
shell okay so let me do this put a
couple around oxygen like this put two
here for hydrogen to be
sharing and this is what I get but this
is a problem okay because oxygen wants
to have eight but it only has 1 2 3 4 5
6 7 here hydrogen is Happy it has a two
that it wants but oxygen is really
pissed wants one more but it only has
seven total to distribute between these
two atoms so what can we do here well
this oxygen and hydrogen pair they can
steal an electron from somewhere else
and that's exactly what they do here it
is they pull this electron in from
elsewhere and we can say that it gains
one electron they needed this one more
electron in order to make the bonding
work okay but they gained an El and what
happens if you gain an electron you get
a negative charge so by pulling in this
one extra electron to make the bonding
work now this clump of atoms the oxygen
and the hydrogen that are coent bonded
together now they have a charge okay we
can convert this electron dot diagram
into a proper calent bonding diagram
here where I replace the shared pair
with a line okay that means they're
sharing two electrons and then I put
these dots for unshared pairs around the
oxygen and now I put the whole thing in
Brackets with a minus this is what it
looks like and this is a polyatomic ion
okay we call this
hydroxide and its formula is o1 minus
just once again it's an O coal bonded to
an H but in order for this coent bond to
work out in order for both atoms to be
happy they had to grab an additional
electron from the environment and in
gaining that extra electron to make
everything work the whole Clump got a
one minus charge let me show you another
example let's say that one
nitrogen is going to come together with
four
hydrogens let's do the math to figure
out how we're going to draw the Lewis
structure hydrogen is in this First
Column so one one one one each one of
these hydrogens has one veence electron
to donate 1 2 3 4 5 nitrogen is in this
fifth column here so it has five valence
electrons now I want to find out the
total number that we have 5 + 1 + 1 + 1
plus one I lost count of how many I was
doing nine total electrons okay let's
draw the Dot Structure for this nitrogen
is um I only have one nitrogen so
chances are very high that it's going to
be the middle atom I'm going to put that
in the middle and then I'm going to
arrange the hydrogens around it okay so
now I have nine nine electrons to
distribute between these atoms so that
they're all happy nitrogen is going to
want have eight electrons in its outer
valence shell and hydrogen it's happy
with two okay so let's do that we've got
nine electrons to distribute to make all
of these atoms happy
here and if I put an electron between
two atoms it means that those two
electrons are it means that those two
atoms are sharing the electrons and that
a calent bond is formed between them so
here's what we have we have eight
electrons distributed around nitrogen
each of the hydrogens are sharing two
electrons with nitrogen so everything's
happy but I have an additional electron
because you add up all the veence
electrons you get nine so here's a ninth
electron but these guys the nitrogen and
the hydrogen they're like we're already
happy right we we have everything that
we need nitrogen has eight each of the
hydrogen have two they're like What's
the deal here we don't know what to do
with you what are we going to do with
this ninth
electron they Chuck it out they throw it
away so they take this ninth electron
and in order you know for all of them to
be happy they're like get out of here
and they throw it away okay so they
lose one electron this group of atoms
loses an electron if you gain an
electron you get a negative charge if
you lose an electron what happens to you
you get a positive
charge
so this whole thing has just become a
polyatomic ion because it's a clump of
atoms coal bonded together that has a
charge it looks like this if you want to
uh draw the calent bonds between them
with a one plus and we call this
ammonium you might be familiar with it
because it's one of the polyatomic ions
that's on my list ammonium NH
h41 plus just once again it gets this
charge because it has nine total
electrons but it only needs eight is
that eight yeah it only needs eight I'm
really bad with counting it only needs
eight and so it needs to get rid of that
ninth electron and in doing so it loses
it and it gets a positive charge so
there are all these polyatomic ions that
we've talked about as I keep saying just
a small number of them on my list here
but all of them are clumps of atoms held
together with calent bonds and they all
have charges and as you've just learned
the reason why they have charges is
because in order to make the Cove valent
bonds work between these atoms they
either have to gain electrons or they
have to lose electrons and so that's why
these polyatomic ions have a charge to
gain or lose electrons to make the
calent bonding work
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