9th Chemistry Notes Urdu Medium
Important Full Book 9th Chemistry Notes Urdu Medium written by Honorable Sir Mr. Azeem Khan Suib. These notes are very helpful in the preparation of 9th Chemistry Notes Urdu Medium for students of the 9th class Chemistry Urdu Medium and these are according to the paper patterns of all Punjab boards.
Summary and Contents:
Topics which are discussed in the notes are given below:
- Full book important Handwritten Short Questions with Answers of Chemistry in Urdu Medium.
- Chemistry is study of composition and properties of matter. It has different branches.
- Substances are classified into elements and compounds.
- Elements consist of only one type of atoms.
- Compounds are formed by chemical combination of atoms of the elements in a fixed ratio.
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- Mixtures are formed by mixing up elements or compounds in any ratio. They are classified as homogeneous and heterogeneous mixtures.
- Each atom of an element has a specific atomic number (Z) and a mass number or atomic mass (A).
- Atomic mass of an atom is measured relative to a standard mass of C-12.
- Relative atomic mass of an element is the mass of an element compared with 1/12 mass of an atom of C-12 isotope.
- Atomic mass unit is 1/12 of the mass of one atom of C-12, lamu = 1.66 x l0^-24 g.
- Empirical formula is the simplest type of chemical formula, which shows the relative number of atoms of each element in a compound.
- Define industrial chemistry and analytical chemistry.
- How can you differentiate between organic and inorganic chemistry?
- Give the scope of biochemistry.
- How does homogeneous mixture differ from heterogeneous mixture?
- What is the relative atomic mass? How is it related to gram?
- Define empirical formula with an example.
- State three reasons why do you think air is a mixture and water a compound?
- Chapter No: 2 Structure of Atoms
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- Cathode rays were discovered in last decade of nineteen century. The properties of cathode rays were determined and they led to the discovery of electron.
- Canal rays were discovered in 1886 by Goldstein . The properties of canal rays resulted in the discovery of proton in the atom.
- Neutron in the atom was discovered in 1932 by Chadwick.
- First of all structure of an atom was presented by Rutherford in 1911. He proposed that an atom contains nucleus at the center and electrons revolve around this nucleus.
- For what purpose U-235 is used?
- A patient has goiter. How will it be detected?
- Give three properties of positive rays.
- What are the defects of Rutherford's atomic model?
- As long as electron remains in an orbit, it does not emit or absorb energy. When does it emit or absorb energy?
- Chapter No: 3 Periodic Table and Periodicity of Properties
- In nineteenth century attempts were made to arrange elements in a systematic manner.
- Dobereiner arranged elements in a group of three called triads.
- Newlands arranged elements in groups of eight like musical notes.
- Why are noble gases not reactive?
- How is periodicity of properties dependent upon number of protons in an atom?
- Why shielding effect of electrons makes cation formation easy?
- What is the difference between Mendeleev's periodic law and modern periodic law?
- What do you mean by groups and periods in the Periodic Table?
- Chapter No: 4 Structure of Molecules
- Why do atoms react?
- Why is the bond between an electropositive and an electronegative atom ionic in nature?
- Ionic compounds are solids. Justify.
- More electronegative elements can form bonds between themselves. Justify.
- Metals are good conductor of electricity. Why?
- Ionic compounds conduct electricity in solution or molten form. Why?
- What type of covalent bond is form Differentiate between lone pair and bond pair of electrons in nitrogen molecule.
- Chapter No: 5 Physical States of Matter
- What is diffusion, explain with an example?
- Define standard atmospheric pressure. What are its units? How it is related to Pascal?
- Why are the densities of gases lower than that of liquids?
- What do you mean by evaporation how it is affected by surface area.
- Define the term allotropy with examples.
- In which form sulphur exists at 100 °C.
- Chapter No: 6 Physical States of Matter
- Why suspensions and solutions do not show tyndall effect, while colloids do?
- What is the reason for the difference between solutions, colloids and suspensions?
- Why the suspension does not form a homogeneous mixture?
- How will you test whether given solution is a colloidal solution or not?
- Why we stir paints thoroughly before using?
- Chapter No: 7 Electrochemistry
- Define oxidation in terms of electrons. Give an example.
- Define reduction in terms of loss or gain of oxygen or hydrogen. Give an example.
- What is difference between valency and oxidation state?
- Differentiate between oxidizing and reducing agents.
- Differentiate between strong and weak electrolytes.
- How electroplating of tin on steel is carried out?
- Chapter No: 8 Chemical Reactivity
- Why reactivity of metals increases down the group?
- State the physical properties of metals.
- Why nitrogen forms compounds with alkaline earth metals directly?
- Why the second ionization energy of magnesium is higher than the first one?
- How oxygen reacts with group II A metals?
- What is relationship between electropositivity and ionization energy?