CBSE Class 10 Science Revision Notes Chapter 3

CBSE Class 10 Science Revision Notes Chapter 3 – Metals and Non-metals

Class 10 Chapter 3 – Metals and Non-metals covers several concepts, terms, and formulae. It becomes difficult for students to understand and remember them in one go. Hence, Extramarks has provided CBSE Class 10 Science Revision Notes Chapter 3 – Metals and Nonmetals on its official website which will make it easy for students to revise properly. All the Class 10 Science notes have been prepared by experts who have followed the latest CBSE curriculum and NCERT guidelines. In addition to these notes, students can also refer to previous years’ question papers, answer keys, etc.

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CBSE Class 10 Science Chapter 3 – Metals and Non-metals Revision Notes 

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Positions of Metals and Non–Metals in the Periodic Table

Metals are found in the leftmost categories of the periodic table. Group I A elements are highly reactive alkali metals, while group II A elements are alkaline earth metals. Transition metals are elements from groupings II-A and III-A.

Non-metals, except hydrogen, are elements found to the right of the Periodic Table in groups IV-A, V-A, VI-A, and VII-A. These elements get progressively non-metallic as they move down the group. For example, group V-A’s first and second members are non-metals, the third and fourth are metalloids, and the final is metal. Metalloids are a type of element that has characteristics similar to both metals and nonmetals. Some examples of metalloids are boron, silicon, germanium, arsenic, antimony, tellurium, and astatine. To the right of these metalloids are the nonmetals, which contain the element hydrogen.

Physical Properties of Metals

• Physical State: Metals are solid at average temperature, except for mercury and gallium, which are liquids.
• Malleability: Metals that can endure hammering can be fashioned into thin sheets known as foils. Except for zinc, which is highly brittle.
• Lustre: The feature of metals that causes light to reflect off their surfaces is known as luster. This feature of metals can be attributed to polished metal surfaces.
• Ductility: Metals can be used to make wires. Except for zinc, which is highly brittle.
• Conduction: Metals are good conductors because they contain free electrons. Silver and copper are the finest conductors of heat and electricity. Lead is the worst heat conductor. Iron, bismuth, and mercury are all terrible conductors.
• Hardness: All metals are complex, except sodium and potassium, which are soft and may be sliced with a knife.
• Melting and Boiling Point: Metals are distinguished by their high melting and boiling points. Whilst tungsten has the highest melting point, silver has the lowest boiling point. Sodium and potassium have low melting points.
• Density: Metals are heavy and have a high density. Iridium and osmium have the highest densities, whereas lithium has the lowest.
• Sonorous: Metals emit a sound when struck by a solid object. This metal feature is known as sonorous.
• Alloy Formation: Metals join to form an alloy, which is a homogenous metal mixture. Brass is an alloy of copper and zinc.

Physical Properties of Non–Metals

• Physical State: At room temperature, the bulk of nonmetals exists in two of three states of matter: gases (oxygen) and solids (iodine, carbon, sulphur). They have no metallic shine (save for iodine) and do not reflect light. (Except diamond-shaped carbon.)
• Conduction: Non-metals have low thermal and electrical conductivity. (Except for graphite, which transmits heat; additionally, both graphite and gas carbon conduct electricity.)
• Nature: Non-metals are exceedingly brittle and cannot be coiled into wires or pounded into sheets. Except for diamond, which is the hardest mineral on the planet.
• Electronegative character: Non-metals have an electronegative tendency for obtaining or exchanging electrons with neighbouring atoms. As a result, nonmetals are recognized for their electronegative properties.
• Reactivity: They form acidic or neutral oxides when they come into contact with oxygen. As a result, nonmetals are reactive.
• Melting and Boiling Points: Nonmetals are distinguished by their low melting and boiling points.

Comparative Properties of Metals and Non–Metals

Chemical Properties of Metals

As part of Class 10 Chapter 3 Science Notes, the chemical properties of metals are as follows: 

Metals are Electropositive Elements

Metals are extremely reactive. Metals are considered to be electropositive elements because they easily lose electrons and produce positively charged ions. Sodium ions (Na +) are produced by the element sodium. Metals’ electropositive nature allows them to easily create compounds with other elements.

The reaction of Metals with Oxygen

Sodium (Na) and potassium (K) are two of the most reactive metals. Potassium, sodium, lithium, calcium, and magnesium react and burn in the presence of oxygen. Metals in the action group of metals, ranging from aluminium to copper, slowly react in the air to produce metal oxides. Aluminium is the fastest, and copper is the slowest.

• Metal + Oxygen → Metal oxide

• When heated in air, copper reacts with oxygen to generate copper(II) oxide, a black oxide.

2Cu + O2 → 2CuO

             (Copper) (Copper(II) oxide)

• Aluminium forms aluminium oxide: 

4Al + 3O2 → 2Al2O3

(Aluminium) (Aluminium oxide)

• Aluminium oxide reacts in the following manner with acids and bases –

Al2O3 + 6HCl → 2AlCl3 + 3H2O Al2O3 + 2NaOH → 2NaAlO2 + H2O 

(Sodium aluminate)

The reaction of Metal with Water

Metal oxide and hydrogen gas are formed when metals react with water. Water dissolves metal oxides into metal hydroxide. There are, however, some metals that do not react with water.

Metal + Water → Metal oxide + Hydrogen 

Metal oxide + Water → Metal hydroxide

Potassium and sodium, for example, react aggressively with cold water. The reaction between sodium and potassium is so strong and exothermic that the evolved hydrogen quickly catches fire.

2K(s) + 2H2O(l) → 2KOH(aq) + H2 (g) + heat energy 

2Na(s) + 2H2O(l) → 2NaOH(aq) + H2 (g) + heat energy

Calcium’s interaction with water is less violent. The heat produced is insufficient to ignite the hydrogen.

Ca(s) + 2H2O(l) → Ca(OH)2 (aq) + H2 (g) 

Calcium begins to float because the hydrogen gas bubbles that develop adhere to the metal’s surface.

Cold water does not affect magnesium. When it comes into contact with hot water, it produces magnesium hydroxide and hydrogen. It also begins to float as a result of hydrogen gas bubbles adhering to its surface.

2Al(s) + 3H2O(g) → Al2O3 (s) + 3H2 (g) 

3Fe(s) + 4H2O(g) → Fe3O4 (s) + 4H2 (g)

Reaction of Metals with Acids

Metal + Dilute acid → Salt + Hydrogen

When a metal interacts with nitric acid, no hydrogen gas is produced. Because HNO3 is a powerful oxidising agent. It oxidises the generated H2 to water before being converted to any of the nitrogen oxides (N2O, NO, NO2). However, magnesium (Mg) and manganese (Mn) react with extremely dilute HNO3 to produce H2.

Reactions of Metals with Salt Solutions

In solution or molten form, reactive metals can displace less reactive metals from their compounds.

Metal A + Salt solution of B → Salt solution of A + Metal B

Electronic Nature of Metals and Non–Metals

All atoms, except for noble gases, have an incomplete outermost shell. Noble gases have a complete outer shell, making them non-reactive or “inert.”

In most reactive components, electron transfer or electron sharing is used to maintain the stability of noble or inert gases. Metals are elements capable of donating electrons. They lose electrons and hence produce positive ions.

Non-metals are elements capable of accepting electrons. As a result of gaining electrons, they produce negative ions. A metal’s outermost shell has 1 to 3 electrons, whereas a non-metal’s outermost shell has 4 to 8 electrons.

The only two exceptions to this rule are hydrogen and helium. Hydrogen is a nonmetal with one electron in its valence shell, whereas oxygen is a metal with two electrons in its valence shell.

Important Points

• Al0−3e−→Al3 +  
• Donor metals receive a positive charge proportional to the number of electrons donated. Because aluminium has an atomic number of 13, its electrical configuration is 2, 8, and 3. Aluminium contains three electrons in its valence shell; it loses three electrons to form Al3 +.
• Nonmetals receive electrons and obtain a negative charge equal to the number of electrons accepted.

Bonding

The number of valence electrons in an atom governs its propensity to participate in chemical processes (electrons in the outermost shell of an atom). Atoms acquire the oxidised noble gas configuration of eight electrons in the outermost shell via chemical combination (known as the octet rule).

Atoms can be combined in one of two ways: electrovalent bonding or covalent bonding. In all chemical processes, electrons from an atom’s outermost shell interact with other atoms, either through transfer or sharing.

Electrovalent Bonding

When one atom transfers one, two, or three electrons from its valence shell to another atom that can take these electrons, this is known as electrovalency. Because of electrovalency, both of these atoms have the structure of inert gas. When a chemical relationship is created by the transfer of electrons from one element’s atom to the atom or atoms of another, it is referred to as an ionic or electrovalent bond.

Sodium has an electrovalency of 1+ in NaCl, while chlorine has an electrovalency of 1-. Calcium and magnesium have an electrovalency of 2+ in chloride form. In diverse compounds, there are several elements with varied electrovalencies. This is known as ‘changing electrovalency,’ and iron, for example, can be found as ferrous sulphate and ferric sulphate.

Formation of Sodium Chloride

Loss of electrons

Na−→ Na + +e−  

Gain of electron

Cl+e−−→ Cl−

Since sodium has just one electron in its valence shell, it loses one electron during the formation of an ionic connection between the metal sodium and the nonmetal chlorine to complete its octet. It has the properties of a noble gas, neon (2, 8). In its valence shell, the chlorine atom has seven electrons and obtains one to complete its octet while also obtaining stable electronic configurations.

Formation of Magnesium Oxide

Magnesium has the electrical configuration 2, 8, 2 and has an atomic number of 12. Its valence shell contains two electrons. The electronic configuration of chlorine (atomic number: 17) is 2, 8, 7. It has seven valence electrons. Because magnesium has two more electrons than neon (2, 8) and chlorine has one fewer electron than argon (2, 8, 8), one atom of magnesium will seek to find two atoms of chlorine to transfer its two electrons to (one to each), as seen below:

Mg→Mg2 +  +  2e− 

2Cl  +  2e−→2Cl− 

The ion of magnesium (Mg2 + ) and the two ions of chlorine (Cl – )form magnesium chloride which has an ionic bond between them.

 Mg2++2Cl−→[Cl−−Mg2 + −Cl−]→MgCl2

Properties of Electrovalent Compounds

• Ionic compounds have unique features such as physical state, solubility, melting point, boiling temperature, and conductivity. The nature of these features is explained more below.
• Electrovalent compounds are generally rigid crystalline solids due to strong coulombic forces of attraction between oppositely charged ions. Low volatility, high melting and boiling temperatures are seen due to the hardness and high lattice enthalpy.
• Because of the high electrostatic forces, the ions in the solid are unable to move freely and so serve as a poor conductor of electricity in the solid state. However, due to the mobility of the ions in the molten state or in solution, electrovalent compounds become excellent conductors of electricity.
• Ionic compounds have distinct lattice enthalpies because they exist solely as ions packed in a certain three-dimensional arrangement. There is no such thing as a single neutral molecule or ion.
• Ionic chemicals are polar and so soluble in high dielectric constant solvents such as water. The strong interionic interactions are decreased and exist as isolated ions in solution due to ion solvation by solvent molecules.
• Isomorphism occurs in electrovalent substances with the same electrical configuration.

Covalent Bond

A covalent bond is the force of attraction that emerges from the mutual sharing of electrons between two nonmetallic atoms. The combining atoms may share one, two, or three pairs of electrons. A covalent bond is formed by the mutual sharing of electrons between two nonmetal atoms that are similar or dissimilar, which contributes to the stability of both atoms.

When two atoms combine by sharing electrons, each atom assumes the stable configuration of the neighbouring noble gas. Covalent chemicals are those formed by covalent bonding. Bond pairs are the most prevalent type of electron pair.

Formation of Covalent Bonds

How covalent bonds are formed is explained here.

The Hydrogen Molecule

The hydrogen atom (atomic number=1) has one electron in the K shell. It attempts to determine the configuration of helium (Atomic number 2). This is possible if the two connecting atoms’ valence electrons are shared to create a single covalent bond.

H2 is formed via a covalent link between two hydrogen atoms in a hydrogen molecule.

The Oxygen Molecule

Oxygen (atomic number 8) has six valence electrons, two short of the octet configuration. The two oxygen atoms share two pairs of electrons, resulting in two covalent links.

Covalency

The number of electrons that each atom contributes to the exchange of during the formation of a chemical bond is known as a compound’s covalency. The covalency of hydrogen is one in H2, the covalency of oxygen is two in O2, and the covalency of nitrogen is three in N2.

When one or more pairs of electrons in the valence shell of an atom do not engage in bonding, they are referred to as lone pairs or non-bonding pairs of electrons.

Multiple Covalent Bond

Multiple covalent bonds are created when more than one pair of electrons are shared between them.  

General Properties of Covalent Compounds

• Covalent substances don’t exist as ions but rather as molecules. At room temperature, the molecules exist as liquids or gases due to their weak intermolecular interactions. A few substances do exist in the solid form, including urea and sugar.
• The melting and boiling points of covalent compounds are frequently low. This is caused by the weak molecular forces that, at low temperatures, are readily overcome.
• Covalent compounds are often insoluble or marginally soluble in water and other polar solvents. On the other hand, non-polar solvents like benzene and carbon tetrachloride can dissolve in them.
• Covalent compounds are poor electrical conductors when fused or dissolved because they do not create ions in the solution.
• Covalent compound reactions occur between the molecules of the compounds. Covalent bonds in reacting molecules are broken, and new covalent bonds are created in product molecules. These processes are relatively slow since covalent bonds must be broken using energy.

Occurrence of Metals

Minerals and Ores

Metals and their compounds that are found in the crust of the earth are known as minerals. Ores are minerals that can be mined readily and profitably for metals. Ore has metallic complexes with fewer impurities. Therefore, it is evident that not all minerals are ores, but all ores are minerals.

In the Free State

There are very few metals that are found naturally. In the free state, only pure metals like gold, platinum, and mercury are occasionally discovered. In the free state, copper and silver are occasionally found. Such metals are not affected by air or water.

In a Combined State

The rest of the metals are found in various compounds, including oxides, carbonates, sulphides, silicates, chlorides, nitrates, phosphates, and others. In the form of sulphide, oxide, or halide ores, copper and silver can be found in both free and combined forms. 

Since they are so reactive, the metals at the top of the activity series (K, Na, Ca, Mg, and Al) are never found in nature as free elements. Zn, Fe, and Pb, the intermediate metals in the activity series, have a modest level of reactivity. In the earth’s crust, they are mostly present as oxides, sulphides, or carbonates.

Extraction of Metals – Metallurgy

The study of the various procedures used to remove and purify metals from their ores is known as metallurgy.

Concentration – Enrichment of Ores

Ore contains significant amounts of sand and stone particles and is an impure metal. The term “gangue” or “matrix” refers to the ore’s impurities, which include sand, stony minerals, limestone, mica, and other materials. The ore must be cleaned of these impurities before the metal can be recovered. When a chemical called flux is added to the ore to remove the matrix, slag, a fusible substance, is created.

Gangue + Flux = Slag

Using the physical or chemical differences between gangue and the ore, techniques are used to separate the two. The ore is initially ground into a powder. Depending on the kind of ore and its impurities, physical methods, including hydraulic washing, froth flotation, magnetic separation, and chemical treatments are used to separate the crushed ore. Ore “dressing” or “enrichment” are other names for ore concentration.

Physical Methods of Concentration

Here are the physical methods of concentration explained. 

Hydraulic Washing (Gravity Separation)

A hydraulic classifier, which consists of a vibrating, sloping table with grooves that are exposed to a stream of water, processes the ore particles. The denser ore settles in the grooves while the heavier gangue particles are washed away. Using this method, heavy oxide ores of lead, tin, iron, and other metals are concentrated.

Froth Floatation

This method employs a mixture of water and pine oil that is made to foam in a tank to separate sulphide ores. The differing wetting properties of the ore and gangue particles allow for differentiation between the two.

Water, pine oil, detergent, and powdered ore are combined to fill a tank at first. The pressurised air is forced through the pipe of a rotating agitator to create froth. The sulphide ore particles are moistened and coated with pine oil before rising with the foam (froth being lighter). 

Gangue particles that have been submerged in water fall to the tank’s bottom (water being heavier). Because sulphide is more electronegative than oil, covalent oil molecules are pulled to it. Because water has a lower electronegative potential, gangue is drawn to it. The froth with sulphide ore is transferred to a container that is new, dried, and cleaned.

Magnetic Separation

This method enriches magnetic ores like pyrolusite (MnO2) and chromite by taking advantage of the differential in magnetic properties between the ore and gangue particles (FeO.Cr2O3).

Onto a conveyor belt that travels between two magnetic rollers is placed the powdered ore. Compared to the non-magnetic gangue, the magnetic ore particles are drawn to the magnetic roller and move around the conveyor belt for a little longer. The first particles to fall are the gangue particles, creating a heap. Once on the ground, the magnetic mineral fragments form a separate heap. The consequence is the development of two separate heaps of ore and gangue particles.

CBSE Class 10 Chemistry Chapter 3 Notes- Metals and Non-Metals

Class 10 Science Notes Chapter 3 mentioned above is prepared using the CBSE Syllabus. All the important topics are covered. 

Science Chapter 3 Metals and Non-metals Revision Notes- Free PDF Download

Benefits of Class 10 Chemistry Chapter 3 Revision Notes

There are several benefits a student can get from studying the Class 10 Science Notes Chapter 3. Some of them are mentioned here: 

• The grades that students earn on the board exams for class 10 have a big impact on their future.
• Additionally, it is the class where students mentally prepare themselves for the stream they have chosen, which, in part, determines what their future job will be.
• Additionally, class 10 lays the groundwork for your succeeding years. You should thus have a strong foundation in order to have a bright and steady future.

Essential Topics Covered for Revision from Notes of Metals and Non-Metals Class 10 Are as Follows

• Properties of Metals 
• Properties of Non-Metals 
• Chemical Properties of Metals
• Differentiate Between Properties of Nonmetals and Metals
• Reactivity Series of Metals
• Bonding
• The Concentration of Ore
• Conversion of Concentrate to Oxides
• Refining of Metals
• Corrosion of Metals
• Occurrence of Metals

Conclusion

Learning from the Extramarks Class 10 Science Notes for Chapter 3 is the simplest and quickest method. In keeping topics simple, these notes help students stay connected to the core of their curriculum. These notes are highly credible since they are created by the most recent NCERT Syllabus under the supervision of professionals. These notes have been drafted to ensure that the students retain the information.