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Selina Concise ICSE Solutions for Class 8 Chemistry – Chapter wise Exercise Questions solved and important points to remember.  Please click on the links given alongside each of the chapters.  Chapter 1 Matter:  http://matter Chapter 2 Physical and Chemical Changes:  http://physical-and-chemical-changes Chapter 3 Elements, Compounds and Mixtures:  http://compounds-and-mixtures Chapter 4 Atomic Structure:  http://atomic-structure Chapter 5 Language of Chemistry:  http://language-of-chemistry Chapter 6 Chemical Reactions:  http://chemical-reactions Chapter 7 Hydrogen:  http://hydrogen Chapter 8 Water:  http://water Chapter 9 Carbon and Its Compounds:  http://carbon-and-its-compounds

Selina Concise ICSE Solutions for Class 8 Chemistry Chapter 7 Hydrogen Points to Remember: Hydrogen is the most abundant element found in the universe. Hydrogen is much more common in the form of compounds. The most important compound of hydrogen is water. The chief sources of hydrogen are water, acids and alkalies. Hydrogen is prepared by the action of water, acids or alkalies on active metals. Electrolysis of water results in the formation of hydrogen and oxygen. Hydrogen is lighter than air. Hydrogen bums in air with pop sound. Hydrogen acts as a reducing agent. Hydrogen is used to produce oxyhydrogen flame and in weather forecast balloons. Exercise 1. Fill in the blanks: (a)  Hydrogen is  lighter  than air. (b)  Hydrogen is  sparingly  soluble in water. (c)  Hydrogen bums with a  oxyhydrogen pale blue  flame and  pop  sound is heard. (d)  A metal  sodium  hydrogen in the reactivity series gives hydrogen with ...

Selina Concise Chemistry Class 8 ICSE Solutions – Water  Points to Remember: Water is the source of life for all living beings. Water occurs in all the three states of matter i.e. ice, liquid water and water vapours. Water found in nature (i) oceans and seas (ii) rivers and lakes (iii) springs and wells (iv) rain. Rainwater is the purest form of water. Sea water is very impure. Potable water should be free from suspended impurities and harmful germs. Water is a compound, with the molecular formula is H 2 O. The boiling point of water is 100°C and the freezing point is 0°C. 0°C is also called tripple point, because water can exist in all its three states. The specific heat of water is higher than that of any other liquid. It is used as a cooling agent. Water has minimum volume and maximum density at 4°C. This is called anomalous behaviour of water. Water is an universal solvent. The gases dissolved in water have biological importance. They enable aquatic life to sustain itself. Wate...

Selina Concise ICSE Solutions for Class 8 Chemistry Chapter 9 Carbon and Its Compounds Points to Remember: Carbon occurs in the earth’s crust in the free as well as in the combined state. In the free state, it occurs as coal, diamond and graphite. In the combined state, carbon occurs in atmosphere (CO 2 ) natural gas, food nutrients and carbonates. Diamond is the hardest naturally occuring substance known. Fullerenes are discovered only recently. Exercise – I Question 1. Fill in the blanks. (a)   Carbon  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  Allotropy. (c)   Crystalline  and  non-crystalline  are the two major crystalline allotropes of carbon. (d)  Diamond is the hardest substance that occurs naturally. (e)  The name ‘carbon’ is derived from the Latin word  carbo. Question 2. Choose the correct alternative. (a) In a com...

Selina Concise Chemistry Class 8 ICSE Solutions – Atomic Structure Exercise 1. Fill in the blanks. (a) Dalton  said  that atoms could not be divided (b) An ion which has a positive charge is called a  cation. (c) The outermost shell of an atom is known as  valence shell. (d) The  nucleus  of an atom is very hard and dense. (e) Neutrons are  neutral  particles having mass equal to that of protons. (f) Isotopes are the atoms of  an  element having the same atomic number but a different mass number. 2. Write ‘true’ or ‘false’ for the following statements: (a) An atom on the whole has a positive charge. false (b) The maximum number of electrons in the first shell can be 8. false (c) The central pad of the atom is called nucleus. True. 3. Give the following a suitable word/phrase. (a) The sub-atomic particle with negative charge and negligible mass. (b) Protons and neutrons present in the nucleus. (c) The electrons present in the outermost sh...