CBSE Class 10 - Science - CH3 - Metals and Non-Metals

Metals and Non-Metals

Q & A

Q1: List any five physical properties of metals.

Answer: Physical properties of metals are:

1. Metals are usually hard (exceptions are: sodium and potassium).
2. These are sonorous.
3. These are lustrous.
4. Metals exhibit malleability and ductility.
5. Mostly they are solids (exception is mercury)
6. They exhibit high tensile strength.
7. These have high densities.

Q2: Are metals electronegative or electropositive?

Answer: Metals are electropositive i,e. they form cations by loosing electrons.

Q3: Define Malleability.

Answer: Malleability is the property of a metal, by which it can be beaten into thin sheets.

Q4: Name a metal which can be cut with a knife?

Answer: Sodium

CBSE Class 10 - Science - CHEMICAL REACTIONS AND EQUATIONS (MCQs)

CHEMICAL REACTIONS AND EQUATIONS

MCQs

Q1: Which of the following is not a decomposition reaction?

(a) CaCO₃ → CaO + CO₂
(b) H₂ + Cl₂ → 2HCl
(c) H₂CO₃ → H₂O + CO₂
(d) 2KClO₃ → 2KCl + 3O₂

Q2: Which of the following is not an oxidising agent?

(a) Oxygen
(b) Conc. Sulphuric acid
(c) Chlorine
(d) Hydrogen


Q3: The oxidation reaction which produces heat and light is

(a) endothermic
(b) photochemical
(c) combustion
(d) exothermic

CBSE Class 10 - Science - CH 16 - Management of Natural Resources (Q and A)

Management of Natural Resources

Why do we need to use our resources carefully?

Q & A

Q1(CBSE 2011): What is coliform bacteria? What does its presence in water indicate?

Answer: Coliform is a group of bacteria which is found in human intestines. Its presence in water indicates contamination by disease-causing microbes. Its high presence in rivers and ponds elevates the risks of water borne diseases like gastroenteritis.

Q2(CBSE 2011): State two reasons of launching "Ganga Action Plan". Which bacteria was found in Ganga water indicating contamination?

CBSE Class 10 - CH4 - Carbon and Its Compounds (MCQs)

Carbon and Its Compounds

(MCQs)

Q1: Which of the following is an odd compound?

(a) Ethene
(b) Ethane
(c) Propene
(d) Acetylene

CBSE Class 10 - Science - CH5 - Periodic Classification of Elements (MCQs)

Periodic Classification of Elements

Circular Periodic Table
credits:wpclipart

MCQs

Q1(NCERT): Which of the following statements is not a correct statement about the trends when going from left to right across the periods of periodic Table.

(a) The elements become less metallic in nature.
(b) The number of valence electrons increases.
(c) The atoms lose their electrons more easily.
(d) The oxides become more acidic.

CBSE Class 9/10 - Science - All about Names of the Chemical Elements

All about Names of the Chemical Elements

1. There are 115 chemical elements known today to the world. Only 90 are found in nature and the rest are artificially created.

2. A good number of elements are named after human beings and mythological figures.

CBSE Class 10 - Science - Ch14 - Sources of Energy

Sources of Energy 

(Q & A)

Q1: Fill in the blanks.
(a) Hydro power plants convert _________ energy of falling water into electricity.

(b) When wood is burnt in a limited supply of oxygen, ______ is left behind as residue.

(c) Gases like ______, _____, ______ and ______ are generated in a biogas plant.

(d) Biogas contains _____ % methane.

(e) To maintain the required speed of the turbine, wind speed should be higher than _____.

(f) To establish 1 MW generator, the wind energy farm needs about ___ hectares of land.

(g) Ocean Thermal Energy plants can operate if the temperature difference between the water at the surface and water at depths up to ______ km is _______ or more.

(h) ______ and _______ countries have number of power plants based on geothermal energy.

Answer:

CBSE Class 10 - Science - CH3 - Metals and Non-Metals (MCQs)

Metals and Non-Metals

MCQs

Check in Periodic Table
How many metals, non-metals and metalloids?

1. Which of the following is the best electrical conductor?

(a) Gold

(b) Silver

(c) Copper

(d) Aluminium

CBSE Class 10 - Science - CH2 - Acids, Bases and Salts

Acids, Bases and Salts

credits:clker.com

MCQs, NCERT Solutions, Q & A

Q1: The most commonly used indicator in laboratory is
(a) Methyl Orange
(b) Litmus
(c) Phenolphtalein
(d) Universal Indicator

Answer:  Universal Indicator



Q2: Olfactory indicators are:
(a) Clove
(b) Turmeric
(c) Soap
(d) Rose Petals

Answer: (a) Clove

How to learn naming Chemical Formulae?

Chemicals
(src:deviantart)

Nomenclature of Simple Inorganic compounds.

1. A formula is a shorthand notation used to identify the composition of a molecule or compound.

2. For example chemical formula of water is H₂O. It includes the symbol of each element (e.g. Hydrogen:H and Oxygen:O)  in the molecule, along with numerical subscripts to show how many atoms of each element are present.

3. Most of the inorganic compounds are binary compounds i.e. it consists of two elements. Some are ternary i.e. contain more than two elements.

Class 10 - Science - Ch1 - Chemical Reactions & Equations

Ch1 - Chemical Reactions & Equations

MCQs, Q & A, NCERT Solutions

Q1:  A chemical reaction involves in
a. Only breaking of bonds
b. Only formation of bonds
c. Both breaking and formation of bonds
d. None of these

Answer: (c)  Both breaking and formation of bonds

Q2: A balanced chemical equation always obeys
a. Law of conservation of mass
b. Law of thermal equilibrium
c. Law of conservation of energy
d. All of the above

Answer: (a) law of conservation of mass.

CBSE- Class X - Ch5 - Periodic Classification of Elements

Periodic Classification of Elements 

(Chapter Notes and CBSE exam questions and answers)

Modern Periodic Table

Vertical Columns or Groups
There are 18 groups in the periodic table.

1. First group elements are called alkali metals.
2. Second group elements are called alkaline earth metals. They are not as soft as Group 1.
3. Groups three to twelve are called transition elements.
4. Group 1, 2 and 13 - 18 are called normal elements or main group elements or representative elements.
5. Group 16 elements are called chalcogens (except polonium).
6. Group 17 elements are called the halogen family.
7. Group 18 elements are called noble elements (earlier called inert gas group).
8. The lanthanides and actinides which form part of group 3 are called inner transition elements.

Horizontal Rows or Periods
Horizontal Rows are called periods in the Periodic Table. There are seven periods or rows.

CBSE - Class 10 - Ch4 - Soaps and Detergents

Soaps and Detergents

Soap & Detergents (Concept Map)

Q1: Why soap does not work well with hard water containing Ca²⁺ or Mg²⁺ ions?

Answer: Because it reacts with Ca²⁺ or Mg²⁺ to forma white precipitate which is called scum and soap goes waste. Therefore soap forms no or little lather with hard water.

Class 10 - Chapter 4- Carbon and its Compunds (Short Questions & Answers)

Class 10 - Chapter 4- Carbon and its Compounds

Methane Structure

(Short Questions & Answers)

Q1: State whether the following are true or false
       a. Both alkenes and cyclo-alkanes both can be represented by the same general formula.
       b. The general formula C_nH_2n is valid for any alkene with any number of multiple bonds,
       c. Acetone is the common name of propanone.
       d. Isomers always show same chemical properties.


Q2: Which is the common name for ethyne?

Q3: The complete combustion of a hydrocarbon always gives .....?

Q4: What is the term used for the compounds which have same molecular formula but
       different structures?

Class 10 - Science - CH4 - Carbon and Its Compounds (Q & A) (#cbsenotes)(#eduvictors)

Class 10 - Carbon and Its Compounds

cellulose
(credits:wpclipart)

Q1. What is next homologue of C₃H₇OH is called?

Answer: The next homologue of C₃H₇OH is called butanol C₄H₉OH.


Q2. What is the molecular formula of the alcohol which can be derived from propane?

Answer: Propane: CH₃-CH₂-CH₃ or C₃H₈
Alcohol obtained from propane is C₃H₇OH.


Q3. What is meant by the term functional group?

Answer: An atom or a group of atoms, which makes a carbon compound reactive and decides its
properties. is called a functional group.

Q4. Give the names of the functional groups: (CBSE 2007)
          i) -CHO  (ii  -C=O

Answer: (i) Aldehydic group (ii) Ketonic group.

Q5. Give the names of the following functional groups: (CBSE 2007)
         i) —OH (ii) —COOH

Answer: (i) Alcoholic (ii) Carhoxylic.