Learn
Class 10 Metals and Non-metals notes: NCERT Chapter 3 revision
These are short revision notes for Chapter 3 of the NCERT Class 10 Science textbook (Reprint 2026-27), "Metals and Non-metals". They follow the chapter's sections in order: properties, reactions, the reactivity series, ionic compounds, getting metals out of ores, and corrosion. Read them after the chapter, not instead of it.
Keep the textbook open next to these notes. The wording and the summaries are ours; the textbook is the authority.
How much it counts in the board exam
CBSE's Class 10 Science curriculum for 2026-27 puts this chapter in Unit I, Chemical Substances: Nature and Behaviour, worth 25 of the 80 theory marks, together with Chemical Reactions and Equations; Acids, Bases and Salts; and Carbon and its Compounds. CBSE does not split the 25 marks between the four chapters. For this chapter the curriculum names the properties of metals and non-metals, the reactivity series, ionic compounds, basic metallurgy and corrosion.
1. Physical properties (section 3.1)
Metals, in general:
- They shine when the surface is clean (metallic lustre) and are usually hard.
- They can be hammered into sheets (malleable) and pulled into wires (ductile). Gold and silver are the most malleable; gold is also the most ductile, and about 2 km of wire can be drawn from just 1 g of it.
- They carry heat and electricity well and usually melt only at high temperatures. Silver and copper conduct heat best; lead and mercury do it comparatively badly.
- Many ring when struck (sonorous), which is why bells are made of metal.
Non-metals, in general: solids or gases (bromine is the one liquid), dull, brittle, and poor conductors.
The exceptions examiners like:
- Mercury is a metal but liquid at room temperature. Gallium and caesium melt on a warm palm.
- Lithium, sodium and potassium are soft enough to cut with a knife, and light, with low melting points.
- Iodine is a non-metal with a shine.
- Carbon has allotropes (different forms of one element): diamond, the hardest natural substance, with very high melting and boiling points; and graphite, which conducts electricity.
Because of these exceptions, physical properties alone cannot sort every element. Chemical properties do it better.
2. Chemical properties of metals (section 3.2)
With oxygen. Most metals form a metal oxide. Copper heated in air turns black with copper(II) oxide: 2Cu + O₂ → 2CuO (Cu 2 = 2, O 2 = 2). Aluminium: 4Al + 3O₂ → 2Al₂O₃ (Al 4 = 4, O 6 = 6).
- Metal oxides are basic. A few dissolve in water to give alkalis: Na₂O + H₂O → 2NaOH.
- Aluminium oxide and zinc oxide are amphoteric: they react with acids and with bases, giving a salt and water both times. Al₂O₃ + 6HCl → 2AlCl₃ + 3H₂O and Al₂O₃ + 2NaOH → 2NaAlO₂ + H₂O (sodium aluminate).
- Sodium and potassium catch fire in open air, so they are stored under kerosene. Magnesium, aluminium, zinc and lead get a thin oxide skin that protects the metal under it. Silver and gold stay bright: heating them in air does not oxidise them.
- Anodising makes aluminium's oxide skin thicker on purpose, by electrolysis in dilute sulphuric acid with the article as the anode.
With water. Metal + water → metal oxide + hydrogen; a soluble oxide then gives a hydroxide.
| Metal | Reaction with water |
|---|---|
| Potassium, sodium | Violent with cold water; the hydrogen catches fire. 2Na + 2H₂O → 2NaOH + H₂ |
| Calcium | Gentler with cold water; it floats on hydrogen bubbles. Ca + 2H₂O → Ca(OH)₂ + H₂ |
| Magnesium | Only with hot water; it also floats |
| Aluminium, iron, zinc | Only with steam, giving the oxide. 3Fe + 4H₂O → Fe₃O₄ + 4H₂ |
| Lead, copper, silver, gold | No reaction at all |
With dilute acids. Metal + dilute acid → salt + hydrogen. With dilute hydrochloric acid the speed of bubbling gives the order Mg > Al > Zn > Fe; copper does not react. Nitric acid is the special case: it oxidises the hydrogen to water, so no hydrogen comes off, except with magnesium or manganese in very dilute nitric acid. Aqua regia (concentrated HCl and HNO₃, 3 : 1) can dissolve gold and platinum.
With salt solutions. A more reactive metal pushes a less reactive one out of its salt solution. An iron nail in copper sulphate solution gets a copper coat; a copper wire in iron sulphate solution stays the same. So iron is more reactive than copper.
3. The reactivity series (section 3.2.5, Table 3.2)
From most to least reactive: K, Na, Ca, Mg, Al, Zn, Fe, Pb, [H], Cu, Hg, Ag, Au. Hydrogen, in brackets, is not a metal; it is in the list to compare against. Metals above it can give hydrogen gas with dilute acids; copper, mercury, silver and gold cannot.
4. Ionic compounds (section 3.3)
Atoms react to reach a full outer shell, like the noble gases. Sodium (2, 8, 1) gives up one electron and becomes Na⁺ (2, 8). Chlorine (2, 8, 7) takes one and becomes Cl⁻ (2, 8, 8). The opposite charges hold the ions together. Magnesium (2, 8, 2) gives one electron each to two chlorine atoms, forming Mg²⁺ and two Cl⁻ ions: MgCl₂.
A compound made this way, by electrons moving from a metal to a non-metal, is an ionic (electrovalent) compound. Sodium chloride is a large group of ions, not separate molecules.
| Property | Why |
|---|---|
| Hard but brittle solids | The ions attract strongly, but the solid breaks into pieces under pressure |
| High melting and boiling points (NaCl melts at 1074 K) | Breaking the attraction takes a lot of energy |
| Dissolve in water, not in kerosene or petrol | |
| Conduct when molten or dissolved, not as a solid | The ions can move only when the solid is broken up |
5. Getting metals from ores (section 3.4)
Words to know: a mineral is an element or compound found naturally in the earth's crust; an ore is a mineral rich enough in one metal to extract it at a profit; gangue is the sand, soil and other waste mixed with the ore, removed first (enrichment). Metallurgy covers the whole job, from ore to refined metal.
The method depends on where the metal sits in the series:
- Bottom (low reactivity): heat alone. Mercury from cinnabar: 2HgS + 3O₂ → 2HgO + 2SO₂, then 2HgO → 2Hg + O₂. Copper from Cu₂S: 2Cu₂S + 3O₂ → 2Cu₂O + 2SO₂, then 2Cu₂O + Cu₂S → 6Cu + SO₂ (Cu 6 = 6, S 1 = 1, O 2 = 2). Gold, silver, platinum and copper can also be found free.
- Middle (zinc, iron, lead): make an oxide, then reduce it. A sulphide ore is heated strongly with plenty of air (roasting): 2ZnS + 3O₂ → 2ZnO + 2SO₂. A carbonate ore is heated strongly in a limited supply of air (calcination): ZnCO₃ → ZnO + CO₂. Then carbon reduces the oxide: ZnO + C → Zn + CO. A reactive metal can also do the reducing. The thermit reaction, Fe₂O₃ + 2Al → 2Fe + Al₂O₃, gives so much heat that the iron comes out molten; it is used to join railway tracks.
- Top (K, Na, Ca, Mg, Al): electrolysis. Carbon cannot take oxygen from these metals, because they hold on to oxygen more strongly than carbon does. Sodium, magnesium and calcium come from their molten chlorides: the metal collects at the cathode (Na⁺ + e⁻ → Na) and chlorine at the anode (2Cl⁻ → Cl₂ + 2e⁻). Aluminium comes from its oxide the same way.
Refining. Most metals from these steps still carry impurities. Copper, zinc, tin, nickel, silver and gold are purified by electrolytic refining (see the diagram below).
6. Corrosion and alloys (section 3.5)
- Silver turns black (silver sulphide); copper slowly gets a green coat (basic copper carbonate); iron gets brown, flaky rust.
- Iron rusts only when air and water are both present. In the book's three-tube test, nails in boiled water under oil (no air) and nails in dry air do not rust.
- Prevention: paint, oil, grease, galvanising (a thin zinc coat on iron or steel, which still protects if it cracks), chrome plating, anodising, and alloying.
- An alloy is a mixture, uniform all the way through, of two or more metals, or of a metal with a non-metal. Iron with about 0.05% carbon becomes hard and strong; iron with nickel and chromium is stainless steel, which does not rust. Brass is copper and zinc, bronze is copper and tin, solder is lead and tin (low melting point, for joining wires). An alloy with mercury in it is an amalgam. Alloys conduct electricity less well, and melt at lower temperatures, than the pure metals.
- 22 carat gold, the usual choice for Indian jewellery, is 22 parts gold to 2 parts copper or silver; 24 carat gold is pure and too soft.
7. One diagram to practise: electrolytic refining of copper
Draw a rectangular tank about two-thirds full of liquid and label the liquid acidified copper sulphate solution (the electrolyte). Hang two plates in it, not touching. Label the thick left-hand plate impure copper, anode (+) and the thin right-hand strip pure copper, cathode (−). Join both to a battery through a key, with the long (+) side of the cell wired to the impure plate. Draw a few Cu²⁺ ions in the liquid with an arrow from the anode towards the cathode. Under the anode, shade a heap at the bottom of the tank and label it anode mud (insoluble impurities).
When you explain it, say three things: copper leaves the anode and goes into the solution; the same amount of pure copper is deposited on the cathode; soluble impurities stay in the solution, and insoluble ones fall as anode mud. If the question names a different metal M, the anode is impure M, the cathode is a thin strip of pure M, and the electrolyte is a solution of a salt of M.
8. Common mistakes
- Calling every metal oxide basic. Aluminium oxide and zinc oxide are amphoteric.
- Writing hydrogen as a product with nitric acid. Usually it is not given off (see section 2).
- Mixing up roasting and calcination. Roasting is for sulphides, in excess air; calcination is for carbonates, in limited air. Both give the oxide.
- Saying solid salt conducts. It conducts only when melted or dissolved.
- Trying to make sodium or aluminium with carbon. Metals at the top of the series need electrolysis.
- Swapping the electrodes in refining. Impure metal is the anode (+); pure metal builds up on the cathode (−).
- Leaving out one condition for rusting. It needs both air and water.
- Unbalanced equations. Count each kind of atom on both sides, as we did above.
Revise with questions
Test yourself with our 8 Metals and Non-metals practice questions with answers, then try a timed paper: the free Class 10 revision papers include a Science paper in 1, 2, 3 and 5-mark sections. The chapter before this one in the series: Chemical Reactions and Equations, explained.
Where CMDLearn fits
CMDLearn is building an AI tutor for Classes 1 to 10 that explains a step and checks the child's working, but leaves the writing to the child. It is still in development, and no child uses it yet. If you would like to hear when there is something to try, you can join the waitlist.
Sources
All checked on 3 November 2026.
- NCERT, Science, Textbook for Class X, Chapter 3 "Metals and Non-metals" (Reprint 2026-27): sections 3.1 to 3.5, Tables 3.2 to 3.4, Figures 3.9, 3.10 and 3.12, and the chapter summary. ncert.nic.in/textbook/pdf/jesc103.pdf
- CBSE, Science curriculum, Class X, 2026-27 (course structure, Unit I): cbseacademic.nic.in/web_material/CurriculumMain27/SecPart1/Science_SecP1_2026-27.pdf
The facts, section numbers, reactions and examples are from the documents above. All wording, the summary tables and the diagram description are our own; every equation was checked by counting atoms.
Practise this class: Class 10 worksheets, chapter by chapter · free practice, marked instantly · timed revision papers