What Are Ions | Properties of Matter | Chemistry | FuseSchool

FuseSchool - Global Education

27 Jun 201304:45

Summary

TLDRThis educational lesson introduces the concept of ions, which are atoms or molecules with a net electric charge due to the gain or loss of electrons. It explains that positively charged ions, called cations, are formed when atoms lose electrons, while negatively charged ions, known as anions, are created when atoms gain electrons. The lesson uses Na (sodium) and O (oxygen) as examples to illustrate how ions achieve a stable electronic structure similar to noble gases, with metals typically forming cations and non-metals forming anions. It also touches on the common charges of ions from different groups in the periodic table.

Takeaways

🔬 Ions are atoms or molecules that have gained or lost electrons, resulting in a net electrical charge.
⚡ Electrons carry a negative charge, so when an atom loses electrons, it becomes positively charged (a cation), and when it gains electrons, it becomes negatively charged (an anion).
🐱 The term 'cation' can be remembered with the mnemonic 'cats have paws', associating the positive charge with the word 'cation'.
📚 The electronic structure of an atom is often represented with the number of electrons in each shell, and the valence shell is the outermost shell.
📝 When writing the formula of an ion, the charge is indicated as a superscript.
📐 For drawing electronic structures, the atom or ion is enclosed in square brackets with the charge written in the top right corner.
🌀 Ions tend to have a complete outer shell similar to that of a noble gas, which is a stable electronic configuration.
🤔 The lesson encourages self-practice by asking the learner to draw the electronic structures of Ca and Cl, which form ions by losing and gaining electrons, respectively.
🧩 Metals, particularly those in Group 1 and 2, tend to lose electrons to form cations with +1 and +2 charges.
💧 Non-metals like oxygen and fluorine gain electrons to form anions with -2 and -1 charges, respectively.
🔑 Group 3 elements, such as aluminum, form ions with a +3 charge by losing three electrons, while Group 5 elements, like nitrogen, gain three electrons to form ions with a -3 charge.
🔍 Group 4 elements, including carbon, are noted for their tendency to form covalent compounds rather than ionic ones, which is a topic for further exploration.

Q & A

What is an ion?
-An ion is a charged particle that is formed when an atom gains or loses electrons.
What happens when an atom loses electrons?
-When an atom loses electrons, it becomes positively charged and is called a cation.
What is the term for a positively charged ion?
-A positively charged ion is called a cation.
How can you remember the term 'cation'?
-You can remember 'cation' by associating it with 'cats' and 'paws', which both start with a 'c' and 'p' respectively.
What happens when an atom gains electrons?
-When an atom gains electrons, it becomes negatively charged and is called an anion.
What is the term for a negatively charged ion?
-A negatively charged ion is called an anion.
What is the electronic structure of Na before it becomes an ion?
-The electronic structure of Na (sodium) before it becomes an ion is 2, 8, 1.
How does the electronic structure of Na change when it becomes an ion?
-When Na loses its one valence electron, it becomes a positively charged Na+ ion.
What is the electronic structure of O before it becomes an ion?
-The electronic structure of O (oxygen) before it becomes an ion is 2, 6.
How does the electronic structure of O change when it becomes an ion?
-Oxygen gains two electrons to form a negatively charged O2- ion.
Why do ions form the same electronic structure as a noble gas?
-Ions form the same electronic structure as a noble gas because they achieve a stable configuration by filling their outer shell, similar to the noble gases.
What is common between Na and Mg in terms of ion formation?
-Both Na (sodium) and Mg (magnesium) are metals that lose their valence electrons to form cations with a +1 and +2 charge respectively.
Why do non-metals like O and F tend to form anions?
-Non-metals like O (oxygen) and F (fluorine) tend to form anions because they gain electrons to achieve a stable electronic configuration similar to that of a noble gas.
What charge does an oxygen ion typically have?
-An oxygen ion typically has a -2 charge because it gains two electrons to fill its valence shell.
What charge does a fluorine ion typically have?
-A fluorine ion typically has a -1 charge because it gains one electron to fill its valence shell.
How does the group number of an element relate to the charge of its ion?
-The group number of an element often indicates the number of valence electrons it has and thus the charge of the ion it forms. For example, Group 1 metals form +1 ions, and Group 2 metals form +2 ions.
What is the charge of an ion formed by an element from Group 3?
-An element from Group 3, such as aluminium, forms an ion with a +3 charge by losing three electrons.
What is the charge of an ion formed by an element from Group 5?
-An element from Group 5, such as nitrogen, forms an ion with a -3 charge by gaining three electrons.
Why do Group 4 elements like carbon tend to form covalent compounds?
-Group 4 elements like carbon tend to form covalent compounds because they share electrons to achieve a stable electronic configuration rather than gaining or losing electrons to form ions.

Outlines

00:00

🚀 Introduction to Ions and Their Formation

This paragraph introduces the concept of ions, explaining that they are atoms or molecules that have gained or lost electrons, resulting in a net charge. It clarifies that electrons are negatively charged, so an atom that loses electrons becomes a positively charged cation, while an atom that gains electrons becomes a negatively charged anion. The paragraph uses the mnemonic 'cats have paws' to help remember that cations are positive. It provides examples of sodium (Na) and oxygen (O) forming ions, emphasizing the importance of including the charge in both written formulas and electronic structure diagrams. It also explains that ions strive to achieve a stable electronic configuration similar to that of a noble gas.

Mindmap

Keywords

💡Ions

Ions are atoms or molecules that have an unequal number of protons and electrons, resulting in a net electrical charge. They are fundamental to the theme of the video, which is to explain how ions are formed by the gain or loss of electrons. For example, when an atom like sodium (Na) loses an electron, it becomes a positively charged ion, or cation.

💡Electrons

Electrons are negatively charged subatomic particles that orbit the nucleus of an atom. They play a crucial role in the formation of ions, as the video explains that atoms become ions by gaining or losing electrons. The video uses the example of oxygen (O) gaining two electrons to become an anion with a -2 charge.

💡Charge

In the context of the video, charge refers to the electrical property of an ion resulting from an imbalance in the number of protons and electrons. A positive charge indicates a deficiency of electrons (as in cations), while a negative charge indicates an excess of electrons (as in anions). The video emphasizes that the charge is a key characteristic of ions.

💡Cations

Cations are positively charged ions formed when an atom loses one or more electrons. The term is mnemonically linked to 'cats have paws' as a memory aid, as mentioned in the video. The video uses sodium (Na) as an example, illustrating how it loses its valence electron to become a positively charged Na+ ion.

💡Anions

Anions are negatively charged ions that form when an atom gains one or more electrons. The video explains that anions have a complete outer shell, similar to noble gases, and uses oxygen (O) as an example, which gains two electrons to form a negatively charged O2- ion.

💡Valence Electrons

Valence electrons are the outermost electrons of an atom and play a significant role in chemical bonding. The video discusses how the gain or loss of these electrons leads to the formation of ions, such as sodium losing its one valence electron to become a cation.

💡Noble Gases

Noble gases are a group of chemical elements that are stable due to having a full set of valence electrons. The video mentions that ions have the same electronic structure as the nearest noble gas, indicating a stable configuration, which is why atoms tend to form ions to achieve this structure.

💡Metals

Metals are elements that tend to lose valence electrons to form cations. The video explains that metals like sodium (Na) and magnesium (Mg) are metals that form cations by losing electrons, with group 1 metals losing one electron to form +1 charged ions and group 2 metals losing two electrons to form +2 charged ions.

💡Non-metals

Non-metals are elements that tend to gain electrons to form anions. The video discusses how non-metals like oxygen (O) and fluorine (F) gain electrons to achieve a stable electronic structure, with oxygen gaining two electrons to form an O2- ion and fluorine gaining one electron to form an F- ion.

💡Electronic Structure

The electronic structure of an atom refers to the arrangement of electrons in its orbitals. The video emphasizes that when atoms form ions, their electronic structure changes to resemble that of a noble gas, achieving a stable configuration. This is illustrated by the examples of Na+ and O2- ions.

💡Group 1 Metals

Group 1 metals, also known as alkali metals, are located in the first column of the periodic table and have one valence electron. The video explains that these metals lose their single valence electron to form cations with a +1 charge, as demonstrated with sodium (Na).

💡Group 2 Metals

Group 2 metals, also known as alkaline earth metals, are found in the second column of the periodic table and have two valence electrons. According to the video, these metals lose both valence electrons to form cations with a +2 charge, using magnesium (Mg) as an example.

💡Group 6 Elements

Group 6 elements, which include oxygen, are located in the sixth column of the periodic table and have six valence electrons. The video mentions that oxygen, being a group 6 element, gains two electrons to form an O2- ion, achieving a stable electronic structure.

💡Group 7 Elements

Group 7 elements, also known as halogens, are in the seventh column of the periodic table and have seven valence electrons. The video explains that fluorine, a group 7 element, gains one electron to form an F- ion, completing its outer shell.

Highlights

Lesson on understanding ions and their formation.

Atoms develop a charge when they gain or lose electrons.

Electrons are negatively charged, influencing the charge of atoms.

Charged particles resulting from electron gain or loss are called ions.

Atoms that lose electrons become positively charged cations.

Mnemonic for cations: 'cats have paws'.

Atoms that gain electrons become negatively charged anions.

Example of Na ion formation with electronic structure notation.

Writing and drawing the charge of ions in formulas and structures.

Oxygen as an example of anion formation with electronic structure.

Ions achieve a complete outer shell similar to noble gases.

Interactive prompt to draw electronic structure of Ca.

Ca and Cl ions formation and their electronic structures.

Importance of specifying charges in ion formulas and structures.

Commonality between Na and Mg as metals forming cations.

Metals in Group 1 and 2 lose valence electrons to form +1 and +2 charged ions.

Non-metals like O and F gain electrons to form anions.

Oxygen gains two electrons to form O2- and fluorine gains one to form F-.

Group 3 elements like aluminium form +3 charged ions.

Group 5 elements like nitrogen form -3 charged ions.

Group 4 elements like carbon tend to form covalent compounds.

Conclusion summarizing ion formation and types.