StudyTory

 Class 10 - Carbon and Its Compounds  Most Important Questions :-  Q1. Why carbon cannot gain or lose four electrons ?  Answer :-  Carbon cannot gain four electrons because when it gain four electrons then 10 electrons over 6 protons will make the element unstable and therefore it cannot gain four electrons. Carbon cannot lose four electrons because to lose four electrons large amount of energy is required which is not possible , therefore, losing four electrons is not possible for Carbon  Q2. What are covalent compounds? Why are they different from ionic compounds? List their three characteristic properties.  Answer: Covalent compounds are those compounds which are formed by sharing of valence electrons between the atoms e.g., hydrogen molecule is formed by mutual sharing of electrons between two hydrogen atoms. They are different from ionic compounds as ionic compounds are formed by the complete transfer of electrons from one atom to another e.g., N...

  Class 10 - Metals and Non metals Most important questions:-  Q 1 .Write the 5 properties of metals with examples. Answer :-  • Metals are lustrous.  E.g - Silver • Metals are Good Conductor of heat . E.g - Silver and copper. • Metals are Ductile . E.g - Gold  • Metals are malleable. E.g - Gold and Silver  • Metals are Hard . E.g - chromium  Q2 . Which of the Following non metal is Lustrous :-  a) Carbon  b) Iodine  c) Chlorine d) Graphite Answer - b) Iodine Q3. Which metal remains in liquid form at room temperature ?  Answer - Mercury Q4. Which Non metal is best conductor of electricity?  Answer - Graphite  Q5 .Which Non metal is best conductor of heat ?  Answer - Diamond  Q6. Generally, when metals are treated with mineral acids, hydrogen gas is liberated, but when metals (except Mn and Mg) are treated with HNO3, hydrogen is not liberated. Why? Answer: Most metals do not react with HNO3 because nitric acid is ...