CBSE Class 11 - Chemistry - CH1 - Mole Concept

Q1: Define mole

Answer: A mole (or mol) is defined as the amount of substance which contains equal number of  particles (atoms / molecules / ions) as there are atoms in exactly 12.000g of carbon-12.

One mole of carbon-12 atom has a mass of exactly 12.000 grams and contains 6.02 × 10²³ atoms.

A mol is just a number like a dozen. A dozen equals to 12 eggs , a gross of Pencil equals to 144 Pencil. Similarly, mol is equal to 6.022 × 10²³(Avagadro constant). Mol is also known as chemist dozen.

CBSE Class 8 - Science - Ch4 - Metals and Non-Metals #eduvictors

Metals and Non-Metals

Class 8 - NCERT Chapter Solutions

Q1. Which of the following can be beaten into thin sheets?
(a) Zinc
(b) Phosphorus
(c) Sulphur
(d) Oxygen

Answer: (a) Zinc, as it is a metal. The rest of these are non-metals.

Q2. Which of the following statements is correct?
(a) All metals are ductile.
(b) All non-metals are ductile.
(c) Generally, metals are ductile.
(d) Some non-metals are ductile.

Answer: (c) Generally, metals are ductile.
Mercury (metal) is liquid at room temperature and cannot be drawn into wires. Therefore, it is non-ductile.

NTSE examination shifts to class 10

NCERT announced the date of NTSE examination for class 10. Earlier the examination was conducted for students of standard 8.
Stage I (State)
Last Date for Submission of Application Form                             - 31st August, 2012

Examination in Mizoram, Meghalaya, Nagaland and
Andaman and Nicobar Islands                                                       - 17th November, 2012 (Saturday)



Examination in All other States and                                               - 18th November 2012 (Sunday)
Union Territories


Stage II (National)
Examination in All States and Union Territories                           - 12th May, 2013 (Sunday)

CBSE - Class 9 - Science - CH8 - Motion (WorkSheet) #eduvictors

Class 9 - Ch8 - Motion

Fill in the blanks

1. If the position of an object does not change with time, it is said to be at _____.

2. Rest and Motion are ___________ (absolute/relative) terms

3. The study of motion without taking into account the cause of motion is called ______ (kinematics/dynamics).

4. An object is said to be at ________ (rest/motion) if it changes its position with respect to its surroundings in a given time

Class 9 - Maths - History of Indian Mathematics - MCQs

Aryabhatta - statute at
University of Astrophysics at Pune
image credits: wikipedia

History of Indian Mathematics - MCQs

(Questions taken from MP Board Question bank for class 9.)
(Answers are provided at the end)

Q1: Main branch of Mathematics is :
(a) Arithmetic
(b) Algebra
(c) Geometry
(d) Accountancy

Q2: Which is the base of scientific development?
(a) Physics
(b) Chemistry
(c) Mathematics
(d) None of these

One Word Substitution (English Grammar)

One Word Substitution

In competitive examinations (BITSAT, NDA, University Graduate entrance...), often there are questions on 'one word substitution'. Here is a list to help you.

One word substitution is also important to write or speak something very precisely. Class 10 grammar has a topic 'Avoid repetition' covering about it.

1. Anarchist: One who promotes revolt against government.
2. Convalescent: One who is recovering from illness.
3. Omnipotent: One who is all powerful.
4. Omnipresent: One who is present everywhere.

CBSE Class 11 - Physics - CH2 - Error Analysis #PhysicsNotes #eduvictors

Error Analysis

Q1: Define error.

Answer: The exact measurement of a physical quaintly is not possible. This is known as Heisenberg's uncertainly principle. Uncertainty in the measurements is called error.

Numerically, the deviation of the measured value from the actual value is called an error.  If X is the quantity measured, then ΔX is called error in X. i.e. Error = Actual value - Measured value.

English Reading Comprehension (Set-2)

Reading Comprehension

Q1 (CBSE 2011 Class 9 Exam): Read the passage carefully.

It is about nine in the morning and a scraggly bunch of kids is waiting near an abandoned building in Lodhi Colony for their school to arrive. The school is a bright yellow bus kitted out with cabinets, a blackboard, a water dispenser, a ladder, a canopy, teaching aids and an LCD TV.  They call it the Mobile Learning Centre or school-on-wheels. When the bus arrives, it parks parallel to the pavement, the television is turned to face the road and an inspirational song is played loud enough to draw the attention of children.

CBSE Class 10 - English (Comm.) Workbook - AVOIDING REPETITION

Unit 9 - AVOIDING REPETITION

A. Notice the element of repetition in the following sentences and decide whether it is acceptable or not. Give reasons in support of your opinion.

Answer:

Sentence	Opinion
1. Democracy is the government of the people, by the people, for the people.	Its a famous quote, otherwise 'the people' is repeated. (Acceptable)
2. "I want to scale Mt. Everest, I want to do scuba diving and I want to fly an aeroplane. Actually, I want to do a lot of things before I die."	'I want' is repeated number of times. (Not Acceptable)
3. New Delhi has many big, big malls.	'big' is repeated. (Only acceptable in spoken English)
4. In this article first I have tried to discuss the various causes of air pollution. Then I have tried to discuss the various effects of air-pollution and finally I have tried to discuss various ways to reduce the amount of air-pollution.

Branches of Biology

Eye of Jumping Spider
Photo by Thomas Shahan; Source: Flickr

Branches of Biology

1. Biology: study of  living organisms.

2. Botany:  study of plants.

3. Zoology: study of animals.

4. Morphology: study of internal and external structures of organisms (plants and animals) organs.

5. Histology: study of tissues.