❖ In a chemical reaction, at least one of the following will occur:
 ❖ Chemical equation: A symbolic representation of the reactants, products and their physical states.

 ❖ Balanced chemical equation: Here, the total number of atoms on the reactant side is equal to the total number of atoms on the product side.

 ❖ How to balance an equation  
❖ Exothermic reactions: In these types of reactions, heat is released.
 
❖ Endothermic reactions: In these types of reactions, heat is absorbed.
 
❖ Types of reactions  ❖ Corrosion – The process of coating up of a metal by a layer of some other substance due to the presence of some external substances (such as acids and moisture) is called corrosion.
 
❖ Rancidity – The process of oxidation of fats and oils leading to the change of their taste and smell is called rancidity.Chapter 2: Acids, Bases and Salts
 
 ❖ Acids: These are the substances having sour taste. They turn the colour of blue litmus to red.
 
❖ Base: These are the substances having bitter taste. They turn the colour of red litmus to blue.

❖ Indicator: It is a dye that gives different colours in acids and/ or bases. Turmeric is a natural indicator.

❖ Reaction with metals:
Acid + Metals → Salt + Hydrogen gas
Zn + H₂SO₄ → ZnSO₄ + H₂
Base + Metals → Salt + Hydrogen gas
Zn + 2NaOH → Na₂ZnO₂ + H₂

❖ Reaction of acids with metal carbonates and metal hydrogen carbonates
Metal carbonate/Metal hydrogen carbonate + Acid → Salt + Water + CO₂
Na₂CO₃ + 2HCl → 2NaCl + H₂O + CO₂

❖ Metal oxide + Acid
Metal oxide + Acid → Salt + Water

❖ Non-metal oxide + Base
Non-metal oxide + Base → Salt + Water

❖ Acid–Base reaction
Acid + Base → Salt + Water
NaOH + HCl → NaCl + H₂O

❖ In water solution:
Acid releases H⁺ ion
H⁺ + H₂O → H₃O⁺
HCl + H₂O → H₃O⁺ + Cl^–
Base releases OH^– ion
$\mathrm{NaOH} \stackrel{{\mathrm{H}}_2\mathrm{O}}{\to } {\mathrm{Na}}^{+} + {\mathrm{OH}}^{\mathit{-}}$ ❖ pH → The measure of acidity or alkalinity (Measured on a scale of 0 to 14)
pH 7 → Neutral solution
pH < 7 → Acidic solution
pH > 7 → Basic solution
Human body pH = 7.0 – 7.8
Change in pH in body causes → Tooth decay, stomach pain, burning pain (Honey bee)

❖ Common salt (NaCl) : Has pH = 7

 
 ❖ Bleaching powder → CaOCl₂ (calcium oxychloride) ❖ Baking soda → NaHCO₃ (Sodium hydrogen carbonate)
❖ Washing soda → Na₂CO₃.10H₂O
❖ Plaster of Paris → ${\mathrm{CaSO}}_4 . \frac{1}{2}{\mathrm{H}}_2\mathrm{O}$ Chapter 3: Metals and Non-metals
 
 ❖ Metals
❖ Non-metals
❖ Metals + Non-metals
 

❖ Physical properties of Ionic compounds  ❖ Extraction of metals  
❖ Less active metals
    $\left.2\mathrm{HgS} + 3{\mathrm{O}}_2 \stackrel{ }{\to 2\mathrm{HgO} + {\mathrm{SO}}_2} \right\} \mathrm{Heated} \mathrm{in} \mathrm{air}$

❖ Moderately active metals Chapter 4: Life Processes
 
 ❖ Life processes: Continuously perform the functions of maintenance in living organisms.
     Examples: digestion, respiration, circulation etc.

 ❖ Nutrition: Process of obtaining nutrients from the environment. Two types- autotrophic and heterotrophic  
 ❖ Respiration  
❖ Transportation  
❖ Excretion: Involves removal of harmful metabolic wastes from the body. Chapter 5: Control and Coordination
 
❖ Control and coordination: Working together of various integrated body systems in response to changes in the body for maintenance of bodily functions.
❖ Parts of the nervous system
❖ Tropic movement
❖ Chemical coordination in plants
❖ Chemical coordination in animals Chapter 8:  Sources of Energy
 
❖ Qualities of a good fuel/source of energy are:  
❖ Factors to be considered for choosing fuel are:  
❖ Conventional sources of energy:
❖ Non-conventional sources of energy
❖ Thermal power plant – Coal and petroleum are burned to produce heat

❖ Hydro power plant – (Renewable source)
❖ Technological improvement Chapter 7:  Magnetic Effects of Current
 
❖ Properties of magnetic field lines
❖ Magnetic field lines of current carrying wire
❖ Right-hand thumb rule:
When thumb is in direction of current, the curl of fingers gives direction of circular magnetic field.
  
❖ Corkscrew rule
If one drives a corkscrew in the direction of the current, then the direction in which the handle is turned is the direction of the magnetic field on the magnetic field lines.
 
❖ Solenoid
Solenoid is a cylindrical coil having many turns of insulated wires wrapped closely. When current is passed through the coil, a magnetic field is produced along the axis of the coil.

 

❖ Direction of force on a current carrying conductor in a magnetic field can be given by Fleming’s left-hand rule.
   
 
❖ Application of magnetic force – Electric motor
When current is passed through a coil kept in a magnetic field, a force acts on it which rotates the electric motor.

❖ Electromagnetic Induction
Generation of a current in the conductor due to a varying magnetic field (moving magnet, or moving conductor)
❖ Direction of induced current in a conductor moving in a magnetic fierld can be given by Fleming’s right hand rule.
    Chapter 6:  Electricity
 
❖ Electric current: Amount of charge flowing per unit time.
     $$\begin{gathered} I=\frac{Q}{t} I=\mathrm{current} \\ Q=\mathrm{net} \mathrm{charge} \mathrm{flowing} \\ t = \mathrm{time} \end{gathered}$$

❖ Unit: I → Ampere $1\mathrm{A} = \frac{1\mathrm{C}}{1\mathrm{s}}$
    Q → Coulomb (C)
    t = Second (s)
 
❖ Potential difference:
    The potential difference between two separate points is defined as the work done to move a unit positive charge from one point to another.
    $V=\frac{W}{Q}$
 
❖ Unit: $\mathrm{Volt}, 1 \mathrm{Volt} =\frac{1 \mathrm{joule}}{1 \mathrm{coulomb}} \boxed{\begin{array}{c}1\mathrm{V} = 1\mathrm{J} {\mathrm{C}}^{-1}\end{array}}$
❖ Ohm’s law:
Under constant physical conditions (i.e., constant temperature, pressure etc.), the current flowing through a conductor is directly proportional to the potential difference across the conductor. ❖ Factors on which resistance depends  
❖ Net resistance of resistors in series connection
    R_net = R₁ + R₂ + R₃ + … + R_n

❖ Net resistance of resistors in parallel
    $\frac{1}{R_{net}}=\frac{1}{R_1}+\frac{1}{R_2}+...+R_n$

❖ Heating Effect of current, heat produced depends on:
❖ Application: Electric iron, toaster, fused wire
    Fuse wire: a low-melting point wire connected in series with electric devices for safety.

❖ Electric power: $P=VI=I^{2}R=\frac{V^2}{R}$ Chapter 1: Carbon and Its Compounds
 
❖ Covalent bonds: The bonds formed by the sharing of electrons are known as covalent bonds.

❖ Carbon contains four electrons in its valence shell. It always forms covalent bonds as it is difficult for it to lose or gain four electrons in order to complete its octet.

❖ Allotropy: The property of an element to exist in different forms. Example: Diamond, graphite and buckminsterfullerene are the three allotropes of carbon.
   
❖ Catenation: The ability of an element to combine with itself through covalent bonds. Carbon can combine with itself to form chain, branched, and ring structures.

❖ Hydrocarbons: These are compounds of carbon and hydrogen.

❖ Saturated compounds: The compounds of carbon that contain only single bonds among carbon atoms. Example: alkanes

❖ Unsaturated compounds: The compounds of carbon having double and/ or triple bonds. Example: alkenes, alkynes  

Hetero atom	Name of functional group	Formula of functional group
Chlorine/Bromine	Halo- (Chloro/Bromo)	–Cl, –Br
Oxygen	Alcohol	–OH
	Aldehyde	–CHO
	Ketone	>C=O
	Carboxylic acid	–COOH

	Functional group	Prefix/Suffix	Example
1.	Halogen	Prefix: chloro, bromo, etc.
2.	Alcohol	Suffix: -ol
3.	Aldehyde	Suffix: -al
4.	Ketone	Suffix: -one
5.	Carboxylic acid	Suffix: -oic acid
6.	Double bond (alkenes)	Suffix: -ene
7.	Triple bond (alkynes)	Suffix: -yne

 
❖ Chemical properties of carbon compounds  
❖ Ethanol (CH₃CH₂OH)
❖ Ethanoic acid (CH₃COOH)
❖ The two ends of molecules of soaps and detergents are different. Their one end is hydrophilic and the other is hydrophobic. Presence of these two types of ends is responsible for the cleansing action of soaps.Chapter 2: Periodic Classification of Elements
 
❖ The earliest classification was based on grouping the known elements as metals and non-metals.

❖ Law of Triads: Given by Dobereiner. He was the first person to illustrate the relationship between the atomic masses of elements and their properties. A set of elements showing triads is as under:


❖ Law of Octaves: Given by Newlands. He arranged the known elements in the increasing order of their atomic masses. The law is applicable only to the elements having low atomic masses.
 

❖ Mendeleev’s periodic law: Mendeleev gave a periodic law which states that the properties of elements are a periodic function of their atomic masses.
❖ Modern periodic law:  It states that the properties of elements are a periodic function of their atomic numbers, not their atomic masses. Chapter 4: Heredity and Evolution
 
❖ Heredity: Transmission of characteristics or traits from parents to offsprings

❖ Variations: Difference among individuals of a species and also, among offsprings of same parents. Variations are of two types- heritable and non-heritable

❖ Basis of heredity: each trait is influenced by both maternal and paternal DNA

❖ Mendel’s work
❖ Heredity at cellular level
❖ Sex determination in humans
❖ Evolution
❖ Evolutionary relationships Chapter 6:  Human Eye and the Colorful World

❖ Important components of the human eye
❖ Nearest focal distance of lens = 25 cm

❖ Common defects in eye
❖ Prism


❖ Dispersion
 

❖ Atmospheric refraction
❖ Scattering: Tyndall effect
Atmospheric particles, smoke, tiny water droplets, suspended particles of dust, and air molecules scatter sunlight. Therefore, the path of light becomes visible. Chapter 3: How Do Organisms Reproduce
 
❖ Reproduction
❖ Asexual reproduction  
❖ Sexual reproduction   Chapter 7: Our Environment

❖ Environment: natural surroundings and external conditions of an organism, which include all living and non-living factors that affect the organism

❖ Organism: is the basic unit of an ecological hierarchy, can be unicellular such as Amoeba and Paramecium or multicellular such as humans

❖ Population: a group of individuals of the same species inhabiting a given geographical area at a particular time and functioning as a unit

❖ Community: includes all individuals of different species living within a certain geographical area

❖ Ecosystem: includes both living and non-living components of an area    Chapter 8: Management of Natural Resources
 
❖ Natural resources
❖ 3R principle to save environment   
❖ Need to manage resources
❖ Type of Natural Resources
❖ Stakeholders in forest resources
❖ Water resources
❖ Coal and petroleum
❖ Sustainable Management Chapter 5: Light, reflection and refraction

❖ Reflection of light is the change in the path of a light ray upon collision with an interface of two medium.

❖ Laws of reflection:
❖ Terms related to spherical mirrors
❖ Concave mirror and nature of image formed

⚬ Torch reflector ⚬ Search light ⚬ Vehicle headlight

⚬ Dentist’s mirror ⚬ Shaving mirror

❖ Convex mirror and nature of image formed
❖ Mirror formula: $\frac{1}{f} =\frac{1}{v} + \frac{1}{u}$          
For concave, f  → –ve, for convex, f  → +ve         
Magnification $=\frac{\mathrm{Image} \mathrm{height}}{\mathrm{Object} \mathrm{height}} =-\frac{v}{u}$

❖ Laws of refraction
❖ Refractive index (R.I.)

Medium (Optically denser) = m > 1 →
Optically rarer = m < 1 →
In all medium

❖ Terms related to spherical mirrors
❖ Convex lens and nature of image formed
❖ Concave lens and nature of image formed
❖ Lens Formula:$\frac{1}{f} =\frac{1}{v} - \frac{1}{u}$
    For concave lens f = –ve, convex lens f = +ve

❖ Magnification,$\mathrm{m} =\frac{\mathrm{Image} \mathrm{height}}{\mathrm{Object} \mathrm{height}} =\frac{v}{u}$

❖ Lens power P (Unit dipotre) $=\frac{1}{f (\mathrm{in} m)}$