Category: Selina ICSE Solutions

EXERCISE-5A Q1. What do you understand by the term up thrust of a fluid? Describe an experiment to show its existence.Solution:A b  ody experiences an upward pull when it is partially or fully submerged in a liquid. An upthrust is the term for this upward thrust.The experiment below can be used to show upthrust:Use an […]

EXERCISE-6A Q1. What is heat? Write its S.I. unit.Solution:The energy of the body’s molecular constituents’ haphazard motion is known as heat.“Joule” is its SI unit. Q2. Two bodies at different temperatures are placed in contact. State the direction in which the heat will flow.Solution:A hot body (one with a greater temperature) will transfer heat to […]

Exercise – I Q1. Name the four main sources of water.Answer:(i) Oceans(ii) Seas(iii) Rivers(iv) Lakes Q2. State the importance of water cycle in nature.Answer:(i) Water cycle helps in regulating weather on the earth.(ii) Water cycle makes water available in various forms on the earth. Q3. Why is water very precious for all living beings?Answer:One of […]

Q1. (a) Define a chemical reaction.(b) What happens during a chemical reaction?(c) What do you understand by a chemical bond?Answer:(a) A chemical reaction is any alteration of matter that entails the creation of one or more compounds having wholly distinct characteristics.b) Chemical bonds between atoms or molecules are broken during chemical reaction clusters of atoms […]

Exercise: Q1. Define:(a) Matter(b) Intermolecular force of attraction.Answer:(a) Anything that has mass, takes up space and can be perceived by our senses is considered to be matter. Example: Air, book.(b) The molecules of matter are constantly moving and are held together by an attraction between them known as the intermolecular force of attraction. Q2. What […]

Exercise Q1. Define:(a) Radical(b) Valency(c) Molecular formulaAnswer:(a) Radical: An atom of an element or a collection of atoms from other elements that behave as a single unit and have a positive or negative charge on them is referred to as a radical.(b) Valency: The quantity of electrons that an atom’s valence shell contributes to or […]

EXERCISE Q1. Define: (a) a physical change, (b) a chemical change. Give two examples for the above changes.Answer:(a) A physical change is a temporary alteration in which the original substance’s does not change and its physical characteristics, such as colour, condition, shape, and size, may change. Example: Boiling of water, Melting of ice.(b) A chemical […]

Exercise 1. Fill in the blanks:(a) Hydrogen is __________ than air.(b) Hydrogen is __________ soluble in water.(c) Hydrogen bums with a __________ flame and __________ sound is heard.(d) A __________ hydrogen in the reactivity series gives hydrogen with water.(e) Hydrogen reacts with metal oxides to form __________ and __________.(f) Oxidation is the removal of __________ […]

Exercise – I Q1. Fill in the blanks.(a) __________ is present in both living and non-living things.(b) The tendency of an element to exist in two or more forms but in the same physical state is called __________.(c) __________ and __________ are the two major crystalline allotropes of carbon.(d) __________ is the hardest substance that […]