Introduction ‘Sour’ and ‘Bitter’ taste of food is due to acids and bases. If someone has acidity you give them basic solution such as a baking soda, ENO etc. which are basic in nature and neutralize the acid. The acids and bases nullify each others effect. Acids are sour in taste - They turn Blue Litmus Red Bases are bitter in taste - They turn Red Litmus Blue. Natural Indicators - Litmus, Turmeric, Cabbage Leaves, Petals of flowers such as Petunia , Hydrangea and Geranium Li

Difference between Metals and Non-Metals Substances can be categorized by comparing their physical and chemical properties. Anodizing - It is a process of forming a thick oxide layer of Aluminium. Aluminium develops a thin oxide layer when exposed to air. This Aluminium oxide coat makes it resistant to further corrosion. Clean Aluminum is made the anode and is electrolyzed with dilute H2SO4 The oxide layer can be dyed to give attractive finish to Aluminum. What is Aqua-Regia

Chemical substances containing carbon are referred to as carbon compounds. Carbon is a versatile element that forms the basis for all living organisms and many of the things we use. The amount of carbon present in the earth’s crust and in the atmosphere is quite meagre. The earth’s crust has only 0.02% carbon in the form of minerals (like carbonates, hydrogencarbonate, coal and petroleum) and the atmosphere has 0.03% of carbondioxide. Bonding in Carbon – The Covalent Bond A c

At presently, 118 elements are known to us. Out of these 118, only 94 are naturally occurring. All these have different properties. Classification of Elements Elements are classified on the basis of similarities in their properties. Dobereiner’s Triads In the year 1817, Johann Wolfgang Dobereiner, tried to arrange the elements with similar properties into groups of three elements each. So, he called these groups ‘triads’. Dobereiner's Triad: Li Ca Cl Na Sr Br K Ba I He showed

Introduction Animals and Plants show movement with change in environment. Any change in our environment is associated with movement that may be voluntary or involuntary. This movement is a result of coordination and control between different organs and upon analysis of the environment. In multi-cellular organisms this coordination is done by specialized tissues. Coordination System in Animals - Nervous System The control and coordination in animals is done by nervous and musc

Why do organisms reproduce? Reproduction is not an essential life process but yet all animals and plants reproduce and spend their energy in nurturing their young ones. Reproduction is done to ensure the continuity of their species on earth by passing on similar characteristics to the new individuals through DNA (Deoxyribose Nucleic Acid) present in the cell nucleus. Why is there variation in different individuals? DNA essentially is a blueprint of body design and is the info

Introduction Genetics deal with study of Hereditary and Variation. The transmission of traits/character from one generation to next generation is called Hereditary. The difference in characters/traits between parents and offspring is called Variation. Accumulation of Variation during reproduction Variations appearing during reproduction depends whether organisms multiply sexually or asexually. If multiply asexually If multiply sexually - Variations are fewer. - Occurs due to

What is Light? We are able to see the objects when light is reflected back from them. Therefore, light is a form of energy that allows us to see. Light is a form of electromagnetic radiation and thus does not require any medium to travel. We are able to see through a transparent medium when light passes through it. When light is absorbed completely by an object we are unable to see it as no light bounces off it. Nature and Properties of Light 1. Light has dual nature: Light p

The Human Eye The human eye uses light and enables us to see objects around us. The human eye is one of the most valuable and sensitive sense organs. It enables us to see the wonderful world and the colours around us. On closing the eyes, we can identify objects to some extent by their smell, taste, sound they make or by touch. It is, however, impossible to identify colours while closing the eyes. Thus, of all the sense organs, the human eye is the most significant one as it

What is an Charge? Charge is a fundamental particle in an atom. It may be positive or negative. Like charges repel each other and unlike charges attract each other. Charge on 1 electron (e) = - 1.6 × 10⁻¹⁹ C Charge on 1 proton (p) = 1.6 x 10⁻¹⁹ C S.I. unit of charge = Coulomb (C) 1 Coulomb charge = Charge present on approx. 6 × 10¹⁹ electrons Or We can say that, Charge on 1 electron (e) = - 1.6 × 10⁻¹⁹ C Q = ne ; n = number of electrons e = charge of electron

Introduction What is a Magnet? Magnet is defined as a material that can produce its own magnetic field. There are three types of magnets: 1. Permanent magnet 2. Temporary magnet 3. Electromagnet What is a Compass Needle? A compass needle is a small magnet. Compass needle gets deflected on passing current through a metallic conductor. It’s one end, which points towards north is called North Pole, and the other end, which points towards south, is called a South Pole. Magnetic F

“There is enough on Earth for everybody’s needs, but not enough for everybody’s greed”. – Mahatma Gandhi. What is Energy? Energy is the ability to do work or the total power derived from our natural resources like the Sun, the Oceans, Fossil fuel, Wind, etc. Energy in the usable form, is dissipated to the surroundings (in form of

“Taking care of the Environment is not an obligation. Our Environment is our Life” - Sadhguru Introduction Environment refers to the surrounding of an organism where it thrives. It constitutes both living and non-living things, i.e., physical, chemical and biotic factors. It is a dynamic interaction of climatic factors, living things and natural resources. All of these elements have a direct impact on human survival and economic activities. The environment in totality i

Introduction Natural resources are substances obtained from the planet that are used to sustain life and provide for human needs. A natural resource is something that comes from nature that humans use. Natural resources include things like forests, wildlife, coal and petroleum stone, sand, metals, oil and natural gas. Air, sunlight, soil, and water are other natural resources. The wellbeing of people depends on natural resources. We cannot survive without the fresh water we d

Introduction We can say a chemical reaction has taken places if we observe- • ︎ Change in state • ︎ Change in color • ︎ Evolution of a gas • ︎ Change in temperature or release of energy Whenever a chemical change occurs, we can say that a chemical reaction has taken place such as in fermentation of grapes, souring of milk, rust on iron, respiration etc. Magnesium(Mg) ribbon burns with a dazzling white flame and changes into a white powder. This powder is magnesium oxide (MgO)

What are Life Processes? Movements over very small scale are invisible to us. Molecular activity that takes place in our body cannot be seen by naked eye. But these movements are necessary for creation of new cells and repairing and maintenance of the existing or damaged cells in our body. The maintenance of any living tissue requires energy which is obtained by molecular movements in the bodies of various organisms which make life possible. These 4 processes are interconnect