S. No Reversible Reaction
Irreversible reaction
(i) Reversible reaction can be reversed under suitable conditions. Reversible reaction cannot be reversed. (ii) Both forward and backward reactions take place simultaneously. It is unidirectional It proceeds only in a forward direction. (iii) It attains equilibrium. Equilibrium is not attained. (iv) The reactants cannot be converted completely into products. The reactants can be completely converted into products. (v) It is relatively slow. It is fast.

(i) The temperature of a reaction increases, the adding heat provides energy to break more bonds of the reactant molecules.
(ii) So more reactants ions increases, produce more products.
(iii) Thus speed of the reaction increases.

KCI_(aq) + AgNO_3(aq) ⟶ AgCl_(s) ↓+ KNO_3(aq)
white precipitate of AgCl is formed in aqueous solution of potassium nitrate.

Electronic wastes are generated from the spoiled, outdated, non - repairable electrical and electronic devices such as computers, calculator, toys etc.

i) Non-renewable energy.
ii) Formation of these fuels is a very slow process and takes very long period of time for renewal.

If the habitat of wild animals is disturbed it affects the biological diversity and revenue through tourism.

Hydrogen bond which binds the nucleotides in a DNA.

The dominant character or trait is axial white flower.

Dihybrid cross is a cross in which inheritance of two pairs of contrasting characters are studied.

(i) Epinephrine (Adrenaline)
(ii) Norepinephrine (Noradrenaline)
(iii) They are together called as "Emergency hormones" secreted during emergency situation in man.

Growth hormone, Thyroid hormone, Parathormone and Glucocorticoids.

2,4 - Dichlorophenoxy Acetic acid ( (2,4 - D)

The characters on the background of a Scratch window are known as Sprite. Usually a cat appears as a sprite when the Scratch window is opened. The software provides facilities to make alternations in sprite.

The script editor where you edit programs or your sprites pictures. The script editor has three main parts.
i) Script area
ii) Block menu
iii) Block palette.

Scratch is a software used to create animations, cartoons and games easily. Scratch, on the other hand, is a visual programming language. It is developed in the Massachusetts Institute of Technology (MIT). Media Lab to make programming easier and more fun to learn.

Genetic engineering is the manipulation and transfer of genes from one organism to another organism to create a new DNA called as recombinant DNA (rDNA)

Dee-geo-woo-gen (DGWG).

Atlas 66 is a protein rich wheat variety having higher dietary fibre and protein.

Every year May 28 is observed as menstrual hygiene day.

The enzyme present in acrosome of sperm is hyaluronidase.

The germination of pollen grains takes place in stigma.

(i) The hypothalamus is the link between the endocrine and nervous systems.
(ii) The hypothalamus produces releasing and inhibiting hormones, which stop and start the production of other hormones throughout the body.

Hind brain is formed of three parts (1) cerebellum, (2) pons and (3) medulla oblongata.

(i) 'Stimulus' refers to the changes in the environmental condition, that are detected by receptors present in the body. 
(ii) A receptor is a cell or a group of cells that receives the stimuli.
(iii) An effector is a part of the body which can respond to a stimulus.

Palaeontology.

Archaeopteryx.

Homologous organs.

Coronary artery supply blood to the heart.

Plasma, proteins and blood cells.

RBCs impart red colour to the blood due to the presence of the respiratory pigment hemoglobin.

Insulin deficiency occurs due to destruction of \(\beta \)-cells of the pancreas.

Type-2 Non-Insulin Dependent diabetes mellitus.

Lung cancer, bronchitis and pulmonary tuberculosis, emphysema, Hypoxia, increased blood pressure, gastric and duodenal ulcers.

(i) Aquatic animals live more in cold regions.
(ii) More amount of dissolved oxygen is present in the water of cold regions.
(iii) This shows that the solubility of oxygen in water is more at low pressure.

(i) Volume percentage is defined as the percentage by volume of solute (in ml) present in the given volume of the solution.
(ii) Volume Percentage = \(\frac{Volume \ of \ the \ solute}{Volume \ of \ the \ solution \ +\ Volume \ of \ the \ solvent}\) x 100

(i) A solution must at least be consisting of two components ( a solute and a solvent ).
(ii) Such solution which are made of one solute and one solvent (two components) are called binary solution.
(iii) e.g: On addition copper sulphate crystals to water.

CNS stand for Central Nervous System.

Lungs are attached to the two bronchi.

Respiration takes place through skin.

Glycolysis is the common step in both aerobic and anaerobic pathway.

The carbon that is used in photosynthesis comes from carbon dioxide, or CO₂ that's present in our atmosphere.

When xylem lies towards the centre and phloem lies towards the periphery, it is called collateral vascular bundle.

Becquerel (Bq).

1942 at Chicago, USA.

Boron, Aluminium

Ethanoic acid is prepared by the oxidation of ethanol in the presence of alkaline potassium permanganate or acidified potassium dichromate.

Compound	Carbon chain	Structural formula
(i) Propane	Saturated compounds open chain compounds	CH3-CH2-CH3
(ii) Benzene	Aromatic compounds in carbocyclic compounds
(iii) Cyclobutane	Alicyclic compounds contain one or more Carbocyclic compounds.
(iv) Furan	Heterocyclic compounds contains carbon and other atoms like Oxygen, Nitrogen, Sulphur, etc.,

Simplest Ketone	Structural formula
Acetone

(i) Electric heater.
(ii) Electric iron work on the heating effect of current.

(i) Melting point of tungsten is very.
(ii) Hence it is used in a filament bulb.
(iii) But a fuse wire should be made up of material which has low melting point.

(i) Resistance is inversely proportional to area of cross section. \(\mathbf{R} \alpha \frac{l}{A}\)
(ii) A thicker wire has Iarger area of cross section and hence the resistance decreases.

Dolphins, dogs, bats can hear the ultrasonic vibrations.

The minimum distance required to hear an echo is 1/20^th part of the magnitude of the velocity of sound in air.
i.e.  \(\frac{1}{20} \times 344 = 16.7m\)

(i) The audible range of frequency is 20 Hz to 20,000 Hz.
(ii) These are generated by vibrating bodies such as vocal cords, stretched strings, etc.

Hydrogen chloride (HCl), Hydrogen iodide (HI) are two examples for heterodiatomic molecules.

The total number of atoms present in the molecule is called its atomicity.
\(\text { Atomicity }=\frac{\text { Molecular mass }}{\text { Atomic mass }}\)

(i) Relative atomic mass of an element is the ratio between the average mass of its isotopes to \(\frac{1}{12^{\text {th }}}\) part of the mass of a carbon-12 atom.
(ii) It is denoted as A_r.
(iii) It is otherwise called "Standard atomic weight".

When the temperature of a gas is kept constant, the volume of a fixed mass of  gas is inversely proportional to its pressure. \(\mathrm{P} \alpha \frac{1}{\mathrm{~V}}\)

Linear Expression		Arial Expansion	Superficial expansion
(i)	When a body is heated or cooled, the length of the body changed due to change in its temperature, then the expansion is called as linear expansion.	If there is an increase in the area of a solid object due to heating, then the expansion is called as superficial expansion.	If there is an increase in the volume of a solid due to heating, then the expansion is called as cubical expansion.
(ii)	The ratio of increase in length of the body per degree rise in temperature to its unit length is called as the co-efficient of linear expansion.	The ratio of the increase in ratio of the body per degree rise in temperature to its unit area is called as co- efficient of superficial expansion.	The ratio of the increase in volume of the body per degree rise in temperature to its unit volume is called as co-efficient of cubical expansion.
(iii)	This is otherwise called as longitudinal expansion.	This is otherwise called as Areal expansion.	This is otherwise called as volumetric expansion.

One calorie is defined as the amount of heat energy required to raise the temperature of 1 gram of water through 1^o C.

The ability of the eye lens to focus nearby as well as the distant objects is called power of accommodation of the eye.

S. No.	Convex Lens	Concave Lens
(i)	A convex lens is thicker in the middle than at edges.	A concave lens is thinner in the middle than at edges.
(ii)	It is a converging lens.	It is diverging lens.
(iii)	It produces mostly real images.	It produces a virtual image.
(iv)	It is used to treat hypermetropia.	It is used to treat myopia.

Snell's law state that, the ratio of the sine of the angle of incidence and sine of the angle of refraction is equal to the ratio of refractive indices of the two media.
\(\frac{\sin i}{\sin r}=\frac{\mu_2}{\mu_1}\)

(i) Since, space station and astronauts have equal acceleration, they are under free fall condition.
(ii) Both the astronauts and the space station are in the state of weightlessness.
(iii) They are not actually floating but falling freely around the earth due to the huge orbital velocity.

(i) "According to Newton's second law, the force acting on a body is directly proportional to the rate of change of linear momentum of the body and the change in momentum takes place in the direction of the force".
(ii) Force = mass x acceleration
(iii) F = m x a

(i) The rotating effect of a couple is known as moment of a couple.
(ii) Eg: Turning a tap, winding or unwinding a screw, spinning of a top, etc...
(iii) Moment of a couple = Force x perpendicular distance between the line of action of force.
(iv) M = F x S

(i) Rust is the formation of scaling reddish brown hydrated ferric oxide on the surface of iron containing materials.
(ii) This compound is known as rust and the phenomenon of formation of rust in known as rusting.
(iii) \( 4 \mathrm{Fe}+3 \mathrm{O}_{2}+\mathrm{xH}_{2} \mathrm{O} \rightarrow 2 \mathrm{Fe}_{2} \mathrm{O}_{3} \cdot \mathrm{xH}_{2} \mathrm{O}\\ \quad \quad \quad \quad \quad\quad\text { (Rust hydrated ferric oxide) } \) 

(i) On heating 800^o C, aluminium burns very brightly forming its oxide.
(ii) 4 Al + 3 O₂ → 2 Al₂O₃ (Aluminium oxide)
(iii) A is Aluminium (Al)
(iv) B is Aluminium oxide (Al₂O₃)

(i) A - reddish brown metal - Copper
(ii) When copper is heated at < 1370 K in the presence of oxygen, copper forms black colour Copper (II) oxide (CuO).
(iii) \(2 \mathrm{Cu}+\mathrm{O}_{2} \stackrel{\text { below } 1370 \mathrm{~K}}{\longrightarrow} \underset{\text { (copper (Il)oxide-black) }}{2 \mathrm{CuO}}\)
(iv) When copper is heated at >1370 K in the presence of oxygen, copper forms red colour Cop-per (I) oxide \((\mathrm{Cu}_{2} \mathrm{O} )\)
(v) \(4 \mathrm{Cu}+\mathrm{O}_{2} \stackrel{\text { above } 1370 \mathrm{~K}}{\longrightarrow} \underset{\text { (copper-I-oxide-red) }}{2 \mathrm{Cu_2O}}\)
(vi) A - copper (Cu)
(vii) B - copper (II) oxide (CuO) - Black coloured
(viii) \(\mathbf{C} - copper-I-oxide \left(\mathrm{Cu}_{2} \mathbf{O}\right)-\operatorname{Red}\) coloured