Formation of Ions | Grade 9 Science Quarter 2 Week 3 | MELC Based
Summary
TLDRIn this educational video, the instructor delves into the concept of ion formation for grade 9 science students. Ions, which are charged atoms, are explained as a result of atoms gaining or losing electrons. Metals, with low electronegativity, tend to lose electrons forming cations, while non-metals, with higher electronegativity, gain electrons to form anions. The video illustrates how to determine valence electrons from the periodic table and how to write chemical formulas for ionic compounds, emphasizing the importance of a net charge of zero in compounds.
Takeaways
- đŹ Ions are charged atoms, either positively or negatively, resulting from the gain or loss of electrons.
- đ Metals, with low electronegativity, tend to lose electrons and form positively charged ions called cations.
- đȘ Non-metals, with higher electronegativity, tend to gain electrons and form negatively charged ions called anions.
- đ The number of electrons an atom gains or loses is determined by its valence, which can be found from the group number in the periodic table.
- đ Cations are named after the parent atom, while anions are named by changing the root name of the atom to end with '-ide'.
- 𧩠In the periodic table, group 1 metals form +1 ions, and group 2 metals form +2 ions, while non-metals form negative ions by gaining electrons.
- đ When writing chemical formulas with ions, ensure that the total positive and negative charges balance to zero, reflecting the neutral charge of compounds.
- đ Ionic compounds are formed between metals and non-metals and contain both cations and anions in a way that their charges cancel out.
- đ Understanding the periodic table is crucial for predicting the type of ions formed by atoms and their charges.
- đĄ The video lesson aims to help students explain the formation of ions and how to write chemical formulas involving ions.
Q & A
What are ions?
-Ions are charged atoms, meaning they have either a positive or negative charge due to the gain or loss of electrons.
Why do metals tend to lose electrons?
-Metals tend to lose electrons because they have low electronegativity, which is the ability of an atom to attract electrons.
What is the term for a positively charged ion formed by a metal?
-A positively charged ion formed by a metal is called a cation.
How does the number of valence electrons determine the formation of ions?
-The number of valence electrons, or electrons in the outermost shell, determines how many electrons an atom will gain or lose to form ions.
Why do non-metals tend to gain electrons?
-Non-metals tend to gain electrons because they have higher electronegativity, which makes them more likely to attract or gain electrons.
What is the term for a negatively charged ion formed by a non-metal?
-A negatively charged ion formed by a non-metal is called an anion.
How are anions named differently from cations?
-Anions are named by taking the root name of the atom and changing the ending to '-ide', such as chlorine becoming 'chloride'.
How can you determine the charge of an ion formed by an element in the periodic table?
-You can determine the charge of an ion by looking at the group number in the periodic table; group 1 metals form +1 ions, group 2 metals form +2 ions, and non-metals form negative ions.
What is the rule for writing chemical formulas with ions?
-When writing chemical formulas with ions, the charges must balance out to give a net charge of zero in the compound, ensuring there are equal numbers of positive and negative ions.
Why is it important for a chemical compound to have a net charge of zero?
-A chemical compound must have a net charge of zero to be electrically neutral and stable; this is achieved by balancing the number of positive and negative ions.
How can you find the number of valence electrons of an atom?
-You can determine the number of valence electrons by looking at the group number in the periodic table of elements.
Outlines
đŹ Formation of Ions in Grade 9 Science
This video lesson for Grade 9 science continues from the previous week's topic on chemical bonding, focusing on the formation of ions. Ions are charged atoms, which can be either positively (cations) or negatively (anions) charged. The lesson explains that metals, having low electronegativity, tend to lose electrons and form cations, while non-metals with higher electronegativity gain electrons to form anions. The number of electrons gained or lost corresponds to the valence electrons, which can be determined by the element's group number in the periodic table. The lesson also covers how to name ions, with cations retaining the parent atom's name and anions changing the ending of the element's name. The periodic table is highlighted as a useful tool for predicting the type of ions formed by different elements. Lastly, the lesson touches on writing chemical formulas for ionic compounds, emphasizing that compounds must have a net charge of zero, with equal numbers of cations and anions to balance the charge.
đ Writing Chemical Formulas with Ions
The second paragraph of the video script delves into the practical aspect of ionic chemistry by explaining how to write chemical formulas for compounds formed between metals and non-metals, which are expected to contain ions. These substances are known as ionic compounds. The example of sodium chloride is used to illustrate how the charges of ions must balance out to achieve a net charge of zero in a compound. Each sodium ion carries one positive charge, and the chlorine ion carries one negative charge, ensuring they occur in equal numbers. The lesson concludes by reinforcing the importance of understanding ion formation and encourages students to ask questions and seek clarifications. It also prompts viewers to like, share, and subscribe for more educational content.
Mindmap
Keywords
đĄIons
đĄElectronegativity
đĄCations
đĄAnions
đĄValence Electrons
đĄPeriodic Table
đĄIonic Compounds
đĄNet Charge
đĄChemical Formulas
đĄGroup Number
Highlights
Introduction to the lesson on the formation of ions.
Definition of ions as charged atoms.
Explanation of how ions are formed by atoms gaining or losing electrons.
Metals tend to lose electrons due to low electronegativity.
Formation of positively charged ions, or cations, by metal atoms.
Example of sodium forming a positively charged sodium ion (Na+).
Non-metals tend to gain electrons due to higher electronegativity.
Formation of negatively charged ions, or anions, by non-metal atoms.
Example of chlorine gaining an electron to form a negatively charged ion (Cl-).
Importance of knowing the number of valence electrons for ion formation.
Method to determine the number of valence electrons using the periodic table's group number.
Naming conventions for cations and anions based on the parent atom.
Differentiation in naming anions by changing the root name's ending.
Use of the periodic table to predict the type of ions formed by an atom.
Formation of ionic compounds when metals and non-metals combine.
Writing chemical formulas with ions, ensuring a net charge of zero.
Example of sodium chloride (NaCl) formation and its ionic charges.
Requirement for compounds to have a net charge of zero, balancing cations and anions.
Conclusion of the lesson with an invitation for questions and further engagement.
Transcripts
hi students welcome back to my strong
techie
youtube channel it's already week 3
in our grade 9 science quarter 2 lesson
today's video lesson is the continuation
of our week 2 lesson
if you haven't watched our week 2 lesson
about chemical bonding
you may click the link in the
description box below
our topic for today is about formation
of ions
at the end of this video lesson you are
going to explain
how ions are formed so please keep on
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watching
let us start let us define first
what ions are ions are simply
charged atoms they are neither positive
nor negative meaning they do not have
charge
because the number of protons is equal
to the number of
electrons next
how are ions formed
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ions are formed as atoms gains
or lose electrons
metals tend to lose electrons because
they have
low electronegativity take note class
that electronegativity is the ability of
the atom to attract electrons
when an atom loses electrons it will
form
a positively charged ion and it is
called cat
ions for example sodium is a metal
element
that tends to lose one valence electron
it will form a positively charged sodium
ion or a cut ion
next non-metals tend to gain
electrons because they have higher
electronegativity remember that the
higher the electronegativity
the higher it is to attract or gain
electrons
when an atom gain electrons it will form
a negatively charged ion
called an ions for example
chlorine chlorine is a non-metal element
it can gain an electron from a metal
element such as sodium
to form a negatively charged chlorine
ion take note class
the number of electrons an atom gains or
loses
is its valence so it is important that
you know how to get the number of
valence electrons
or the electrons in the outermost shell
but don't worry
you can determine the number of valence
electron by simply
looking at the group number in the
periodic table of elements
take note of this image
[Music]
again class metal atoms tend to lose
electrons and form a positively charged
ion
called cat ion non-metal atoms tend to
gain electrons and form a negatively
charged ion called
an ion
how do you assign names for an ion
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unlike a cat ion which is named for the
parent atom
an an ion is named by taking the root
name
of the atom and changing the ending
for example chlorine ion taking the root
name
and changing the ending into
it will now be chloride or chloride ion
another one is fluorine into
fluoride ion next
ion charges in the periodic table of
elements
[Music]
we find our periodic table very useful
when we want to know what type of ion is
formed by a given atom
as shown in your screen right now
note that the group 1 metals all form
one positive ions the group 2 metals
all form two positive ions
non-metals on the other hand form
negative ions by gaining
electrons
[Music]
how do you write chemical formulas with
ions
whenever a compound forms between a
metal and a non-metal it can be expected
to contain
ions we call these substances
ionic compounds
[Music]
for example sodium ion
is written in this form chlorine ion
is in this form together it is
sodium chloride
each sodium ion has one positive charge
and chlorine ion has a one negative
charge
so they must occur in equal numbers to
give a net charge
of zero
it is very important to remember that a
chemical
compound must have a net charge of zero
this means that
if a compound contains ions then
there must be both positive ions or cat
ions
and negative ions are what we call an
ions
present and the numbers of cat ions
must be such that the net charge is
zero that is all for our lesson for
today
i hope you learned something new about
the formation
of ions do not hesitate to comment down
below
your questions and clarifications and if
this helped you
do not forget to like share and
subscribe
thanks for watching bye
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