CBSE ADDA

The language of chemistry class 7 Basic science soled questions. Q. What is chemistry? Ans: Chemistry is a branch of science in which we study the composition, structure, properties and change of matter. Q. What is matter? Ans: Anything that is around us having some mass and occupies space is called matter. Q. What are the different classifications of matter? Ans: Matters are classified into element, compound and mixture. Q. What is element? Ans: Elements are the purest form of substance (matter) made up of same kinds of particles. The smallest unit of element is an atom. eg. Hydrogen, oxygen, carbon. Q. What is compound?            See full post   The language of chemistry class 7 Basic science Class 07 Basic sciences Chapter the Language of Chemistry A. Answer these questions 1. What does the formula of a substance tell us? Answer: Formula of a compound or an element represents the name and number of atoms present in one molecule of that compound o

CBSE Class 7 Solved Objective Questions Chapter - Acids, Bases and Salts MCQs 1. The word acid comes from the Latin word ------ which means sour.( acere) 2. The substances used to test whether a substance is acidic or basic are known as ----(indicators) 3. The most commonly used natural indicator is litmus paper . It is extracted from ----(lichens) 4. In acidic solution, litmus paper turns into ------(red) 5. In basic solution, litmus paper turns into ------(blue) 6. In distilled water , litmus paper turns into ------(purple) 7. China rose indicator turns acidic solutions ------and basic solutions to ------ [dark pink (magenta) , green] 8. The reaction between an acid and a base is known as ----- [neutralization] 9. Salt and water are produced in neutralization process with the evolution of heat.[ water] 10. HCl + NaOH ----> ------- +   H 2 O   [NaCl] 11. Our stomach contains -------. It helps us to digest food[hydrochloric acid] 12. indigesti

Read Full Post: 7th Acids bases and Salts [Solved] :  Q1. What are acids? Ans. Acids are the substances which are sour in taste. Q2. What are bases? Ans. Bases are the substances which are bitter in taste & soapy to touch. Q3.Give examples of acids and bases. Ans. Acids- hydrochloric acid, acetic acid, citric acid, lactic acid etc Bases- baking soda, sodium hydroxide, soap etc Q 4. Name the acids present in the following substances. Substance Acid                                     Vinegar acetic acid Curd lactic acid                                 Guava oxalic acid Lemon citric acid                                   Amla citric acid Tamarind tartaric acid Q5. What are indicators? Give examples. Ans. Indicators are the special type of substances which are used to distinguish between acids & bases by showing colour changes. Example: litmus, turmeric, beetroot, China rose extract, phenolphthalein etc. Q6.Name the source from whi

CBSE _ NCERT Class-7th Science   Chapter:  Fibre to Fabric Why a cotton garment cannot keep us as warm in winter? Cotton clothes are thin and do not have spaces in which air can be trapped. thus Cotton clothes do not prevents heat coming out of our body. What is a fibre? A fibre is a long strong thread, which is obtained from natural sources or man made sources. Fibres are classified into two types on the basis of their sources. Plant fibres and animal fibres and synthetic fibres . The fibres, which are obtained from plants and animals are called natural fibres e.g., jute and wool. Animal   fibres are obtained from animals, e.g., silk and wool. Those fibres which are made by the human –beings are known as Man-made or Synthetic Fibres, e.g., Rayon. Match the following: 1. Scouring-- >            Cleaning sheared skin 2. Mulberry leaves ->   Food of silkworm 3. Yak ->                   Wool yielding animal 4. Cocoon ->              Yields sil