Lakhmir Singh Chemistry Class 10 Solutions Page No:131 Question 1: Name one metal and one non-metal which exist in liquid state at room temperature. Solution : Metal – Mercury. Non metal – Bromine. Question 2: Why are metals called electropositive elements whereas non-metals are called electronegative elements ? Solution : Metals are electropositive elements because they can form positive

Lakhmir Singh Chemistry Class 10 Solutions Page No:66 Question 1: What colour do the following indicators turn when added to a base or alkali (such as sodium hydroxide) ? (a) methyl orange (b) litmus (c) red cabbage extract Solution : (a) Yellow. (b) Blue. (c) Green. Question 2: What colours do the following indicators turn when added to an acid (such as

Lakhmir Singh Chemistry Class 10 Solutions Page No:18 Question 1: Why is respiration considered an exothermic process ? Solution : Respiration is an exothermic process because energy is produced during this process. Question 2: On what basis is a chemical equation balanced ? Solution : A balanced chemical equation has equal number of atoms of different elements in the

Lakhmir Singh Physics Class 10 Solutions Page No:269 Question 1: What kind of lens is present in the human eye ? Solution : Convex lens Question 2: Name two parts of the eye which refract light rays (or bend light rays) Solution : Two parts which refract light rays are cornea and eye-lens. Question 3: Name the part of the eye

Lakhmir Singh Physics Class 10 Solutions Page No:219 Question 1: If a ray of light goes from a rarer medium to a denser medium, will it bend towards the normal or away from it ? Solution : It will bend towards the normal. Question 2: If a ray of light goes from a denser medium to a

Lakhmir Singh Physics Class 10 Solutions Page No:173 Question 1: What happens when a ray of light falls normally (or perpendicularly) on the surface of a plane mirror ? Solution : As ray of light falls normally on mirror, this means that angle of incidence is 0o. From second law of reflection, we know that

Lakhmir Singh Physics Class 10 Solutions Page No:121 Question 1: Name a non-renewable source of energy other than fossil fuels. Solution : Nuclear fuels (like uranium) Question 2: Define calorific value of a fuel. Solution : The amount of heat produced by burning 1 gram of a fuel completely is known as its calorific value. Question 3: “The calorific value of

Lakhmir Singh Physics Class 10 Solutions Page No:73 Question 1: State any two properties of magnetic field lines. Solution : Prop of magnetic field lines: (i) The magnetic field lines originate from the north pole of a magnet and end at its south pole. (ii) The strength of magnetic field is indicated by the degree of closeness

Lakhmir Singh Physics Class 10 Solutions Page No:5 Question 1: By what other name is the unit joule/coulomb called ? Solution : Volt Question 2: Which of the following statements correctly defines a volt ? (a) a volt is a joule per ampere. (b) a volt is a joule per coulomb. Solution : (b) a volt is a joule per coulomb. Question

Lakhmir Singh Class 9 CBSE Chemistry Text Book PAGE No 191 Answers Solution 01 Neutron is not present in ordinary hydrogen atom. Solution 02 J. J. Thomson Solution 03 Maximum of 2 e- can be accommodated in K shell of an atom. Solution 04 Maximum of 8 e- can be accommodated in L shell of an atom. Solution 05 Maximum