Mind Map Overal Idea Content Speed Notes Quick Coverage Content : (Scroll down till end of the page) Study Tools Audio, Visual & Digital Content Content … Key Terms Topic Terminology Term Important Tables Table: . Assessments Test Your Learning readmore
Mind Map Overal Idea Content Speed Notes Quick Coverage Content Study Tools Content … Key Terms Topic Terminology Term: Important Tables Topic Terminology Term: Assessments Test Your Learning readmore
Mind Map Overal Idea Content Speed Notes Quick Coverage Plane figure The figures which we can be drawn on a flat surface or that lie on a plane are called Plane Figure. Example – Circle, Square, Rectangle etc. Solid figures The 3D shapes which occupy some space are called Solid Figures. Example – Cube, Cuboid, readmore
Mind Map
Overal Idea
Content
Speed Notes
Quick Coverage
Plane figure
The figures which we can be drawn on a flat surface or that lie on a plane are called Plane Figure.
Example – Circle, Square, Rectangle etc.
Solid figures
The 3D shapes which occupy some space are called Solid Figures.
Example – Cube, Cuboid, Sphere etc. (Scroll down the till the end of the page)
Study Tools
Volume
Space occupied by any solid shape is the capacity or volume of that figure. The unit of volume is a cubic unit.
Surface Area
The area of all the faces of the solid shape is its total surface area. The unit of surface area is a square unit.
Lateral or Curved Surface Area
The surface area of the solid shape after leaving the top and bottom face of the figure is called the lateral surface of the shape. The unit of lateral surface area is a square unit.
Surface Area and Volume of a Cube
Cube is a solid shape having 6 equal square faces.
Lateral surface area of a cube
4s2
Total surface area of a cube
6s2
The volume of a cube
s3
Diagonal
√3 s, s = edge of the cube = side length of face of cube
Surface Area and Volume of a Cube
Example
What is the capacity of a cubical vessel having each side of 8 cm?
Solution
Given side = 8 cm So, Volume of the cubical vessel = l3 = (8)3 = 256 cm3.
Surface Area and volume of a Cuboid
Cuboid is a solid shape having 6 rectangular faces at a right angle.
Lateral surface area of a cuboid
2h(l + b)
Total surface area of a cuboid
2(lb + bh + lh)
Volume of a cuboid
lbh
Diagonal
l = length, b = breadth, h = height
Surface Area and volume of a Cuboid
Example
What is the surface area of a cereal box whose length, breadth and height is 20 cm, 8 cm and 30 cm respectively?
Solution
Given, length = 20 cm, breadth = 8 cm, Height = 30 cm
Total surface area of the cereal box = 2(lb + bh + lh)
= 2(20 × 8 + 8 × 30 + 20 × 30)
= 2(160 + 240 + 600)
= 2(1000) = 2000 cm2.
Surface Area and Volume of a Right Circular Cylinder
If we fold a rectangular sheet with one side as its axis then it forms a cylinder. It is the curved surface of the cylinder. And if this curved surface is covered by two parallel circular bases then it forms a right circular cylinder.
Curved surface area of a Right circular cylinder
2πrh
Total surface area of a Right circular cylinder
2πr2 + 2πrh = 2πr(r + h)
The volume of a Right circular cylinder
πr2h
r = radius, h = height
Surface Area and Volume of a Right Circular Cylinder
Surface Area and Volume of a Hollow Right Circular Cylinder
If a right circular cylinder is hollow from inside then it has different curved surface and volume.
Curved surface area of a Right circular cylinder
2πh (R + r)
Total surface area of a Right circular cylinder
2πh (R + r) + 2π(R2 – r2)
R = outer radius, r = inner radius, h = height
Surface Area and Volume of a Hollow Right Circular Cylinder
Example
Find the Total surface area of a hollow cylinder whose length is 22 cm and the external radius is 7 cm with 1 cm thickness. (π = 22/7)
Solution
Given, h = 22 cm, R = 7 cm, r = 6 cm (thickness of the wall is 1 cm).
Total surface area of a hollow cylinder = 2πh(R + r) + 2π(R2 – r2)
= 2(π) (22) (7+6) + 2(π)(72 – 62)
= 572 π + 26 π = 598 π
= 1878.67 cm2
Surface Area and Volume of a Right Circular Cone
If we revolve a right-angled triangle about one of its sides by taking other as its axis then the solid shape formed is known as a Right Circular Cone.
Curved surface area of a Right Circular Cone
πrl = πr[√(h2 + r2)]
Total surface area of a Right Circular Cone
πr2 + πrl = πr(r + l)
The volume of Right Circular Cone
(1/3) πr2h
r = radius, h = height, l = slant height
Surface Area and Volume of a Right Circular Cone
Surface Area and Volume of a Sphere
A sphere is a solid shape which is completely round like a ball. It has the same curved and total surface area.
Curved or Lateral surface area of a Sphere
4πr2
Total surface area of a Sphere
4πr2
Volume of a Sphere
(4/3) πr3
R = radius
Surface Area and Volume of a Sphere
Surface Area and Volume of a Hemisphere
If we cut the sphere in two parts then is said to be a hemisphere.
Curved or Lateral surface area of a Sphere
2πr2
Total surface area of a Sphere
3πr2
Volume of a Sphere
(2/3) πr3
r = radius
Surface Area and Volume of a Hemisphere
Example
If we have a metal piece of cone shape with volume 523.33 cm3 and we mould it in a sphere then what will be the surface area of that sphere?
Mind Map Overal Idea Content Speed Notes Quick Coverage A quadrilateral has 10 parts – 4 sides, 4 angles and 2 diagonals. Five measurements can determine a quadrilateral uniquely. (Scroll down till end of the page) Study Tools Audio, Visual & Digital Content Practical Geometry Five measurements can determine a quadrilateral uniquely. A quadrilateral can readmore
A quadrilateral has 10 parts – 4 sides, 4 angles and 2 diagonals. Five measurements can determine a quadrilateral uniquely. (Scroll down till end of the page)
Study Tools
Audio, Visual & Digital Content
Practical Geometry
Five measurements can determine a quadrilateral uniquely.
A quadrilateral can be constructed uniquely if the lengths of its four sides and a diagonal is given.
A quadrilateral can be constructed uniquely if its two diagonals and three sides are
known.
A quadrilateral can be constructed uniquely if its two adjacent sides and three angles
are known.
A quadrilateral can be constructed uniquely if its three sides and two included angles
Mind Map Overal Idea Content Speed Notes Quick Coverage Any process that involves the rearrangement of structure of the substance or conversion of reactants into products is defined as Chemical Reaction. For a Chemical Reaction to occur, the change can be observed in the form of – Content Study Tools Audio, Visual & Digital Content readmore
Mind Map
Overal Idea
Content
Speed Notes
Quick Coverage
Any process that involves the rearrangement of structure of the substance or conversion of reactants into products is defined as Chemical Reaction.
For a Chemical Reaction to occur, the change can be observed in the form of –
Change in State: Melting of ice into water.
Change in Colour: Iron rusting which has colour change from silver to reddish brown. (Scroll down till the end)
Content
Study Tools
Audio, Visual & Digital Content
Chemical Reactions and Equations | Study Tools
Chemical Reactions and Equations
Any process that involves the rearrangement of structure of the substance or conversion of reactants into products is defined as Chemical Reaction.
For a Chemical Reaction to occur, the change can be observed in the form of –
Change in State: Melting of ice into water.
Change in Colour: Iron rusting which has colour change from silver to reddish brown.
Change in Temperature: There are two types of reaction i.e Exothermic and Endothermic Reaction.
Exothermic Reactions: Those reactions in which energy is released in the form of heat are called Exothermic Reactions.
Examples –
(1) All combustion reactions e.g.
CH4+ 2O2 —> CO2 + 2H2O + Heat
(2) Thermite reactions e.g.
2A1 + Fe2O3 —> 2Fe + Al2O3 + Heat
Combinations are generally exothermic in nature. The decomposition of organic matters into compost is an example of exothermic reaction.
Endothermic Reactions: Those reactions in which energy is absorbed are called Endothermic Reactions.
Examples –
also, the reaction of photosynthesis –
Evolution of any gas: When Zinc reacts with sulphuric acid it gives hydrogen gas.
Zn + H2 SO4 → ZnSO4 + H2
Formation of Precipitate: When a soluble carbonate reacts with Barium, Barium Carbonate precipitate can be observed.
Change in State
Some chemical reactions are characterised by a change in state.
When wax is burned (in the form of wax candle,) then water and carbon dioxide are formed.
Now, wax is a liquid whereas carbon dioxide is a gas. This means that during the combustion reaction of wax, the physical state changes from solid to liquid and gas.
Physical Change
In this change identity of the substance remains same.
For Example, Melting, Boiling etc.
Chemical Change
The identity of the substances change
Reactants are converted into substance due to formation or broken down of older bonds
Chemical Equation
The symbolic representation of chemical reaction using symbols and formulae is known as Chemical Equation. For this, reactants are written on the left hand side whereas products are written on the right.
Balanced Chemical Equation
A balanced chemical equation is the one where the number of atoms involved in reactants side is equal to number of atoms on product side.
Eq.1. Example of Balanced Chemical Equation
Steps to form Balanced Equation
To show how to balance the equation, the following equation is used-
Fe + H2O → Fe3O4 + H2
Step 1: First of all, draw the boxes around each formula as shown below-
Step 2: Find out the number of atoms of each element. For Example, on reactant side, 1 for Fe, 2 H, and 1 O and on product side we have, 3 for Fe, 4 for O and 2 for H.
Step 3: Start to balance the equation with the compound having maximum number of atoms. While balancing does not alter the formula of the compound.
Step 4: One by one balance each element on reactant and product side.
Step 5: After balancing number of atoms on both the side of the equation, finally check the correctness of the balanced equation.
Step 6: then write the symbols of the physical state of reactants and products as shown below-
3Fe(s) + 4H2O (g) → Fe3O4 (s) + 4H2 (g)
This above equation represents the balanced equation.
Balancing a Redox Reaction
The basic ionic form of the equation is-
Fe2+ + Cr2O72- → Fe3+ + Cr3+
Oxidation half reaction is-
Reduction half reaction is-
Use the reduction half method to balance the equation. Balance the atoms in each half of the reaction except H and O atoms.
Cr2O72- (aq) → 2 Cr3+(aq)
Add water molecules as the reaction is taking place in acidic solution. This is to balance the O atoms and hydrogen ions.
Cr2O72- (aq) + 14 H+(aq) → 2 Cr3+(aq) + 7H2O (I)
Then balance the charges in both half reactions.
Fe2+(aq) → Fe3+(aq) + e–
Cr2O72- (aq) + 14 H+ + 6e– → 2 Cr3+ + 7H2O
6 Fe2+(aq) → 6 Fe3+(aq) + 6e–
Two half of the equations are added to get the overall reaction
Combination Reaction is reaction when single product is formed from the combination of two or more reactants. For Example-
Eq.2. Example of Combination Reaction
Reactions can be exothermic as well as endothermic. Exothermic reaction release heats and raises the temperature of the surroundings. For Example, Respiration is an example of exothermic reaction.
Eq.3. Example of Exothermic Reaction
Endothermic reaction involved the absorption of the heat and thus it cools the surrounding. The decomposition of dead organic material is an endothermic reaction.
Decomposition Reaction is type of reaction which involves breakdown of single reactant into simpler products. Decomposition of silver chloride into silver and chlorine in presence of sunlight is an example of decomposition reaction.
Eq.4. Example of Decomposition Reaction
Displacement Reaction is a reaction in which more reactive element will displaces the less reactive element.
Eq. 5. Example of Displacement Reaction
Double Displacement Reaction is a type of reaction in which cations and anions in the reactants switch the places to form new products.
Eq. 6. Example of Double Displacement Reaction
Redox Reaction is also known as Oxidation-reduction Reaction. In this type of reaction transfer of electrons occurs between the two species. Oxidation is defined as addition of oxygen or removal of hydrogen. Reduction is defined as removal of oxygen or addition of hydrogen. Oxidizing agent is the one which gains the electrons and is reduced in a chemical reaction. Reducing agent is oxidized in a chemical reaction and it loses the electrons. Fluorine is the strongest oxidizing agent. Formic acid is a reducing agent
Eq.7. Example of Redox Reaction
Corrosion
Metals are prone to corrosion. It is a slow conversion of metals into some undesirable compounds. This occur may be due to reaction with oxygen, gases, acids etc. When irons reacts with atmospheric oxygen and moisture, a red layer is formed on the surface of the iron, this process is known as Rusting.
Eq. 8. Equation for Iron Rusting
Rancidity
When food containing fats and oils are exposed to the atmosphere, the oxidation of fat and oil occurs, this is known as Rancidity.
Methods to Prevent Rancidity
Store cooking oils from direct sunlight.
Food should be placed at low temperature.
By adding antioxidants food can be protected from rancidity.
Mind Map Overal Idea Content Speed Notes Quick Coverage In order to provide food for a large population – regular production, proper management and distribution of food is necessary. (Scroll down till end of the page) Study Tools Audio, Visual & Digital Content Crop : When plants of the same kind are grown and cultivated readmore
Mind Map
Overal Idea
Content
Speed Notes
Quick Coverage
In order to provide food for a large population – regular production, proper management and distribution of food is necessary. (Scroll down till end of the page)
Study Tools
Audio, Visual & Digital Content
Crop : When plants of the same kind are grown and cultivated at one place on a large scale, it is called a crop.
In India, crops can be broadly categorised into two types based on seasons – Rabi and Kharif crops. Sowing of seeds at appropriate depths and distances gives good yield.
Good variety of seeds are sown after selection of healthy seeds.
Sowing is done by seed drills.
Soil needs replenishment and enrichment through the use of organic manure introduction of new crop varieties.
Basic practices of crop production: (i) Preparation of Soil: One of the most important tasks in agriculture is to turn the soil and loosen it.
The process of loosening and turning of the soil is called tilling or ploughing.
(ii) Sowing: Sowing of seeds at appropriate depths and distances gives good yield.
Good variety of seeds is sown after selection of healthy seeds. Sowing is done by seed drills.
(iii) Adding Manure and Fertilisers Soil needs replenishment and enrichment through the use of organic manure and fertilisers.
Use of chemical fertilisers
fertilisers has increased tremendously with the introduction of new crop varieties.
Fertiliser: The inorganic compounds containing nutrients such as nitrogen, potassium and phosphorus. They are made in the factories.
Example: ammonium sulphate, potash, etc.
Manure: A natural substance prepared from decomposition of plant and animal wastes (cow dung, animal bones, dead leaves, dead insects and vegetable wastes) by t(he action of microbes.
iv) Irrigation : Supply of water to crops at appropriate intervals is called irrigation. Method of Irrigation: (a)Tradition methods of Irrigation: Moat, Chain pump, Dheki, Rahat.
(b) Modern methods of Irrigation: Sprinkler system, Drip
(v) Protection from Weeds: Weeding involves removal of unwanted and uncultivated plants called weeds.
(vi) Harvesting: Harvesting is the cutting of the mature crop manually or by machines.
(vii) Storage Proper storage of grains is necessary to protect them from pests and microorganisms.
Harvested food grains normally contain more moisture than required for storage.
Large scale of storage of grains is done in silos and granaries to pest like rats and insects.
Farmers store grains in jute bags or metallic bins.
Food is also obtained from animals for which animals are reared.