1. At present about 118 elements are known.
2. Elements can be divided into two main groups: metals and non-metals.
3. Elements which form positive ions by losing electrons are called metals. Thus, metals are the elements which have the tendency to lose electrons.
In this video and subsequent videos, we will focus on Acids and its properties. We'll learn about
- What are Acids?
- What is the role of acid in our life?
- How acids are classified?
CBSE Syllabus for Academic Year 2022-23 is available here.
CH-1: Chemical Reactions and Equations
Deleted- Corrosion and Rancidity (Pg-13)
CH-2: Acids, Bases and Salts
No Reduction
Here is a list of important differences related to the Asexual mode and the Sexual Mode of reproduction, commonly asked in examinations.
Binary Fission vs Multiple Fission
Please note the Board will conduct the annual scheme of assessment at the end of the Academic Session 2022-23
Class 9 Science
Deleted Chapters:
- DIVERSITY IN LIVING ORGANISMS
- NATURAL RESOURCES
- WHY DO WE FALL ILL?
Chapter: NATURAL RESOURCES will be taught in the class and students are encouraged to prepare a brief write up on any concept of this chapter in their Portfolio (internal assessment)
Fill in the blanks with suitable word(s).
1. The generation resulting immediately from a cross of the first set of parents is called ____________.
2. All cells forming the body of an organism, except the reproductive cells are called _________ cells.
3. A type of crossing in which only one pair of contrasting characters is considered is called _________ cross.
Maximum Marks: 50 (40 Theory Paper + 10 Marks Internal Assessment)
Duration: 2 Hours
Weightage Per Paper:
Physics: 12 Marks
Chemistry: 10 Marks
Biology: 18 Marks
Q1: What is the atomic number of a carbon atom?
Answer: 6
Q2: How many valence electrons are present in a carbon atom?
Answer: 4 (electronic configuration is K:2 L:4)
Q3: What are allotropes?
Answer: The property due to which one element exists in more than one form, which differs in physical properties but has similar chemical properties. These forms of an element are called allotropes.
Q1: The laws of reflection hold true for:
(a) plane mirrors only
(b) concave mirrors only
(c) convex mirrors only
(d) all reflecting surfaces
Q2: Focal length of a plane mirror is
(a) zero
(b) infinite
(c) 25 cm
(d) -25 cm
Q1: Which activity is basic to living beings?
(a) Reproduction
(b) Locomotion
(c) Molecular Movement
(d) Adaptation
Fill in the blanks with suitable words
1. An acid is a compound which when dissolved in water gives _________ ions as the only _________ ions.
2. Higher the pH value of a solution, the more __________ it is.
3. pH value of lemon juice is _________ than 7.
Salts/Compounds Colour
1. Potassium dichromate, K₂Cr₂O₇ Orange
2. Potassium permanganate, KMnO₄ Violet
3. Ferric tetra-oxide, Fe₃O₄ Black
4. Ferrous sulphate, FeSO₄.7H₂O Green
5. Ferric sulphate, Fe₂(SO₄)₃ Yellow
6. Ferric hydroxide, Fe(OH)₂ Green
Q1: By what other name is the unit joule/coulomb called ?
Answer: Volt
Q2: Which of the following statements correctly defines a volt ?
(a) a volt is a joule per ampere.
(b) a volt is a joule per coulomb.
Answer: (b) a volt is a joule per coulomb.
Q3: (a) What do the letters p.d. stand for ?
(b) Which device is used to measure p.d. ?
Answer:
(a) p.d. stands for potential difference.
(b) Voltmeter is used to measure p.d.
Chapter: Life Processes (NCERT Book Activity 6.1)
Activity Steps
Step 1: Take a potted plant with variegated leaves – for example, a money plant or croton.
Step 2: Keep the plant in a dark room for three days so that all the starch gets used up.
Step 3: Now keep the plant in sunlight for about six hours.
Step 4: Pluck a leaf from the plant. Mark the green areas in it and trace them on a sheet of paper.
Step 5: Dip the leaf in boiling water for a few minutes.
Step 6: After this, immerse it in a beaker containing alcohol.
Step 7: Carefully place the above beaker in a water bath and heat till the alcohol begins to boil.
What happens to the colour of the leaf? What is the colour of the solution?
Step 8: Now dip the leaf in a dilute solution of iodine for a few minutes.
Take out the leaf and rinse off the iodine solution.
Observe the colour of the leaf and compare this with the tracing of the leaf done in the beginning.
What can you conclude about the presence of starch in various areas of the leaf?
Learning is a continual process. To improve scores, the best way is to learn and practice. Solving question papers help students to evaluate their knowledge and familarise with different types of question patterns being asked in examination.
Eduvictors provides CBSE Previous Year Papers and Sample Question Papers for Class Class 10 Maths, Science, Social, English, Hindi and Sanskrit with/without solutions to help students in their board exam preparation.
1. Buy Most Likely Question Bank - Science: CBSE Class 10 for 2021 Examination
Here attached the Science Sample Question Paper (2020-2021).
Assertion and Reasoning based questions are a bit tricky. You should be able to distinguish whether the assertion is well connected to the reason or these are just random facts. Read both statements carefully, and check if both statements are factually or logically correct or not. If both are correct, then try to check if both are well connected to each other or not.
The questions below consist of statements of an Assertion and a Reason. Use the following key to choose an appropriate answer:
Learning is a continual process. To improve scores, the best way is to learn and practice. Solving question papers help students to evaluate their knowledge and familarise with different types of question patterns being asked in examination.
Eduvictors provides CBSE Previous Year Papers and Sample Question Papers for Class Class 10 Maths, Science, Social, English, Hindi and Sanskrit with/without solutions to help students in their board exam preparation.
1. Buy Most Likely Question Bank - Science: CBSE Class 10 for 2021 Examination
Here attached the Science Sample Question Paper (2020-2021).
Learning is a continual process. To improve scores, the best way is to learn and practice. Solving question papers help students to evaluate their knowledge and familarise with different types of question patterns being asked in examination.
Eduvictors provides CBSE Previous Year Papers and Sample Question Papers for Class Class 10 Maths, Science, Social, English, Hindi and Sanskrit with/without solutions to help students in their board exam preparation.
1. Buy Most Likely Question Bank - Science: CBSE Class 10 for 2021 Examination
Here attached the Science Sample Question Paper (2020-2021) published by Dir. of Education (Delhi).
Based on chemical properties, all compounds can be classified as acids, bases and salts. To identify acids and bases, indicators are used. This video talks about types of indicators i.e. natural, synthetic and olfactory. Examples of indicators and related questions are also covered.
