Properties of Ionic and Covalent Bonds | Grade 9 Science DepEd MELC Quarter 2 Module 2

[Music] hi there have you ever seen sugar and salt side by side without any labels how do you differentiate one from the other [Music] there is a wide variety of compounds and most of these look physically the same like white sugar and table salt it would be easier to determine these two substances by tasting them but this method of identifying substances does not apply to other compounds since some of them can be toxic [Music] compounds are formed between the chemical combinations of two or more elements there are two common types of compounds based on their chemical bonding characteristics ionic compounds and covalent compounds to distinguish between the types of compounds we should first take note of the type of elements that are chemically combined an ionic compound is formed from the combination of a metal and non-metal element on the other hand a covalent compound is formed from the combination of two non-metal elements or a metalloid and a non-metal element [Music] to determine if an element is a metal non-metal or metalloid you can refer to their location in the periodic table the squares colored pink are the metals the blue ones are the non-metals and the green ones are the metalloids as you can see most elements are metals and are placed on the left side of the periodic table except for hydrogen on the right side are the non-metals separated by a stair-like pattern of elements which are the metalloids or semi-metals ionic compounds are formed between a metal and a non-metal the chemical combination between the two types of elements result in the formation of ionic bonds between the atoms ionic bonds are the electrostatic force of attraction that hold cations which are positively charged atoms and n ions which are negatively charged atoms together sodium chloride or table salt is an example of an ionic compound it is the combination of sodium which is a metal and chlorine a non-metal sodium becomes a cation with positively charged atoms as it loses an electron and transfers to the chlorine atom chlorine gaining the electron becomes an anion with negatively charged atoms and eventually an ionic bond is formed holding these ions together here are some examples of common ionic compounds and their uses sodium bicarbonate or what we normally call baking soda is used in baking and as an antacid to reduce stomach acid it can also be used as treatment for indigestion and upset stomach sodium hydroxide is used as a cleaning agent it is the component of soap and detergents now let's move on to covalent compounds covalent compounds are substances that are formed from the chemical combination of two or more non-metallic elements this could be between a non-metal and another non-metal or a metalloid and a non-metal atoms of the different elements are held together in molecules by covalent bonds unlike ionic bonds where electrons completely transfer from one atom to another covalent bonds share their valence electrons the force of attraction between the shared electrons and the positive nuclei of both atoms hold the atoms together in the molecule a molecule is the smallest particle of a covalent compound that still has the properties of the compound table sugar or sucrose is an example of a covalent molecular compound it is a combination of carbon hydrogen and oxygen atoms another example of a covalent bond is water it is the combination of hydrogen and oxygen [Music] hydrogen and oxygen atoms share electrons to form the water molecule this sharing of electrons results in a covalent bond between atoms now let's look at some examples of common covalent compounds and their uses carbon dioxide in liquid and solid form is used as a refrigerant in fire extinguishers it is also an essential gas for plant and animal processes like photosynthesis and respiration but its excessive amount in the atmosphere is unsafe since it contributes to global warming lastly we have water it is one of the most important substances perhaps in the universe water exists in three states of matter and is essential to life processes our body needs water for all our cells tissues and organs it helps regulate body temperature and maintain bodily functions it is also essential for daily and domestic use water also plays an important role in the balance of the ecosystem when sugar and table salt are placed side by side they may appear the same because they are both white crystalline solids we all know that table salt tastes salty and sugar tastes sweet these properties suggest that they are very different substances sugar is a covalent molecular compound made up of sucrose molecules while table salt is an ionic compound made up of sodium chloride ions aside from their taste how are sugar and salt different more specifically how are ionic and covalent bonds different from each other the ionic bond formed between the cations and anions is very strong the ions are arranged in a regular geometric structure called crystal lattice different ionic compounds have different crystal forms naturally occurring ionic crystals are found in rocks and minerals they are mixed with transition metal elements to give rise to brilliant colors have you ever seen some of these rocks and minerals ionic compounds have very high melting and boiling points the ions in a crystal lattice are closely packed together creating a strong electrostatic force of attraction between them the more ions there are in a crystal structure the stronger the ionic bond therefore a large amount of energy is required to overcome these bonds table salt melts at 801 degrees celsius and boils at 1413 degrees celsius ceramics which are made of ionic compounds are an effective heat resistant material suitable for cookware ionic compounds are hard and difficult to separate because of the strong electrostatic attraction between ions but ionic compounds can also be considered brittle for instance when pressure or a mechanical force is applied like striking a hammer on the crystal it will cause charges to move closer this result in electrostatic propulsion which will be enough to split the crystals when ionic compounds are dissolved in water to form an aqueous solution the cat ions and anions are dissociated or separated and are free to conduct electricity through the solution these ionic substances that conduct electricity are referred as electrolytes when an ionic compound like salt is dissolved in water the ions break out individually into cations and anions these ions are then free to move when the electrodes are dipped into the salt solution the cations flow into the negative electrode while the anions flow into the positive electrode causing electricity to flow solid ionic compounds do not conduct electricity instead they are good insulators this is because the ions are locked into its crystal lattice and ions cannot move out so the solid cannot conduct electricity only ionic compounds in liquid molten form or aqueous solutions are good electrical conductors now let's move on to the properties of covalent compounds the covalent bonds between atoms are quite strong but the intermolecular forces or the attraction between molecules can be relatively weak the addition of a small amount of energy separates these molecules easily therefore they have low melting and boiling points in addition covalent bonds are relatively flexible and easy to break which causes molecular compounds to form gases liquids and soft solids at room temperature however there are exceptions primarily when molecular compounds assume crystalline form covalent compounds tend to be more flammable than ionic compounds combustion is a reaction that releases energy when the compound reacts with oxygen to produce carbon dioxide and water many of these molecular compounds that undergo combustion contain hydrogen and carbon atoms ionic compounds dissociate into ions when dissolved in water and ions conduct electricity on the other hand covalent compounds separate into molecules rather than ions when dissolved in water so it typically does not conduct electricity covalent molecular compounds can be polar or nonpolar the polarity of molecules results from the differences in the electronegativity of the bonded atoms electronegativity is the ability of an atom in a molecule to attract shared electrons toward it the greater the electronegativity of an atom the stronger is its ability to attract shared electrons towards itself and away from the less electronegative atom the electrons are not shared equally and part of the molecule carries a partial positive charge while the other part carries a slight negative charge creating a dipole for instance the covalent bonding between hydrogen and fluorine fluorine has an electronegativity of 4.0 while hydrogen has an electronegativity of 2.1 thus fluorine is more electronegative than hydrogen and so the shared electrons spend more time around the fluorine atom creating a partial negative charge this kind of bond is a polar covalent bond when two identical atoms covalently bond with each other like two atoms of fluorine there would be equal sharing of electrons between the fluorine atoms this type of bond is a nonpolar covalent bond to determine if the type of bond is polar or nonpolar one has to consider the electronegativity difference between the bonded atoms the greater the difference the more polar is the bond if the difference in electronegativity is greater than or equal to 2.0 the electrons are completely transferred instead of being shared and an ionic bond would result rather than a covalent bond so to summarize ionic compounds have high melting points and boiling points while covalent compounds are the opposite ionic compounds are hard and brittle while covalent compounds are soft and flexible ionic compounds conduct electricity in aqueous form but do not in solid form at the same time covalent compounds do not conduct electricity at all ionic bonds form crystals and covalent bonds are flammable and can be further classified as polar or nonpolar that's all for now we will be discussing about formation of ions in our next video so stay tuned [Music] see you on our next video and don't forget to keep your minds busy if you like this video please subscribe to our channel and hit the notification icon for more videos like this

Channel: The Learning Bees

Views: 57,004

Keywords: The Learning Bees, Department of Education, DepEd, MELC-Based, Most Essential Learning Competencies, Science, MELC, Grade 9, Chemistry, Covalent bond, Ionic Bond, Polar Covalent bond, Non-Polar Covalent bond, Compounds, Melting Point, Boiling Point, Electrolysis, Electronegativity, Electronegativity difference, Difference between ionic and covalent bond, Properties of ionic and covalent bond, Difference of salt and sugar, valence electron, anion, cation, Is water ionic or covalent bond

Id: T10jabbsVr4

Length: 15min 4sec (904 seconds)

Published: Thu Dec 17 2020