CBSE ADDA

Clasa 9 Science !  Here's a multiple-choice quiz based on chapter Atoms and Molecules chemistry class 9 🎈Topic  🎈Dalton's Atomic Theory: 1. Who is credited with the development of Dalton's Atomic Theory?    a) John Dalton    b) Albert Einstein    c) Isaac Newton    d) Marie Curie 2. According to Dalton's Atomic Theory, atoms are:    a) Indivisible    b) Composed of protons, neutrons, and electrons    c) Made up of smaller particles called quarks    d) Always in a state of motion 3. Dalton's Atomic Theory states that all atoms of a given element are:    a) Identical    b) Different in size and mass    c) Different in chemical properties    d) Composed of protons and electrons 4. In Dalton's Atomic Theory, compounds are formed by:    a) Mixing atoms of different elements together    b) Breaking atoms into smaller particles ...

Matter in our surrounding solved questions Q. 1. What is a matter? Answer: Anything that occupies space and has mass is called a matter.  For example:- Chalk, Milk, Sugar etc. Q. 2. Sodium chloride and sugar have same appearance. Are they same or different? Answer:  They have different physical and chemical properties. So, they are different Q. 3. All substances around us are alike. How? Answer:  All substances can occupy space and have weight. Q. 4. How can we say that air is a matter? Answer:  Air occupies space and have weight. Hence air is a matter. Q. 5. State the characteristics of matter? Matter has mass, weight and occupies space. Q. 6. What are the intensive properties of matter? Answer:  Density, colour, melting point, boiling point, refractive index etc. are the intensive properties of  matter as it does not depend upon the amount of matter contained in it Q. 7. What are the extensive properties of ma...

Chapter : IMPROVEMENT IN FOOD RESOURCES BIOLOGY-STUDY NOTES CLASS 9 INTRODUCTION There is a need to introduce production efficiency of crops and livestock because 1. rapid increase in population 2. No major scope of increasing area of land under cultivation. Increase in food production without degrading our environment   and disturbing the ecological balance i.e. Sustainable Practices are required in agriculture and animal   husbandry. TYPES OF CROPS Cereals: wheat, rice, maize, millets and sorghum. Provide carbohydrates for energy requirements. Pulses: pea, gram, black gram, green gram, pigeon pea and lentil. Provide proteins Oilseeds: soya bean, ground nut, sesame, castor, mustard, linseed and sun flower. Provide necessary  fats. Vegetables, spices and fruits provide vitamins and minerals.  Different crop require different climatic conditions, temperature and photoperiods for their growth  and completion of life cycl...