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โค20๐Ÿค—3๐Ÿฅฐ1
A coordination complexโ€™s core atom/ion is also known as ________?
Anonymous Quiz
19%
a) Bronsted-Lowry acid
36%
b) Lewis base
36%
c) Lewis acid
9%
d) Bronsted-Lowry base
โค6๐Ÿ‘2
๐Ÿ†๐Ÿ’œ๐Ÿ”ค๐Ÿ”ค 1๏ธโƒฃ๐Ÿ”  ๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค ๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ†

๐Ÿงช๐Ÿงช๐Ÿ” 0๏ธโƒฃ๐Ÿ” ๐Ÿ” ๐Ÿ” ๐Ÿ” ๐Ÿ” ๐Ÿ”  ๐Ÿ” ยฉ๏ธ๐Ÿ” ๐Ÿ” ๐Ÿงช๐Ÿงช

1. Any substance made up of multiple repeating units called polymers is referred to as a polymer.

a) Mers
b) Plastic
c) Resins
d) Blocks

Answer: a

2. Which of the following polymers does not fall within the configuration category?

a) Cross-linked
b) Atactic
c) Syndiotactic
d) Isotactic

Answer: a

3. Which of the following is not a thermoplastic example?

a) Polyvinyl chloride
b) Epoxy
c) Polyesters
d) Nylon

Answer: b

4. Which of the following criteria does not apply to polymers?

a) Source
b) Structure
c) Method of preparation
d) Number of monomers

Answer: d

5. Which of the following does not belong in the category of natural polymers?

a) Cellulose
b) Starch
c) Rayon
d) RNA

Answer: c

6. The synthesis of which of the following polymers necessitates the loss of tiny molecules on a regular basis?

a) Polythene
b) Nylon-6,6
c) Buna-N
d) Buna-S

Answer: b

7. The crystallinity rises as the polymerโ€™s brittleness _______.

a) Increases
b) Remains constant
c) Moderate
d) Decreases

Answer: d

8. The polymer absorbs ______ and expands.

a) Water
b) Ether
c) Ethyl alcohol
d) Methanol

Answer: a

9. Short-chained, low-molecular-weight polymers are known as liquid or gas polymers.

a) High-polymers
b) Oligo-polymers
c) Copolymers
d) Homopolymers

Answer: b

10. Which of the following stages of addition polymerization is not one of them?

a) Initiation
b) Recrystallisation
c) Termination
d) Propagation

Answer: b

๐Ÿ” ๐Ÿ” ๐Ÿ” ๐Ÿ” ๐Ÿ” ๐Ÿ” ๐Ÿ” ๐Ÿ” ๐Ÿ” 
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๐Ÿงฟ Radioactivity ๐Ÿงฟ

โž–The process of emission of particles from nuclei because of the nuclear instability; is known as radioactivity.
โž–The substance that releases such energy/rays is known as radioactive substance.
โž–The invisible rays released from such radioactive substance are known as radioactive rays.
โž–Likewise, radioactivity is a nuclear phenomenon that happens (naturally) because of the nuclear instability of atoms.
โž–In 1896 Henri Becquerel first observed the phenomena of radioactivity, but the term โ€˜radioactivityโ€™ was coined by Marie Curie.
โž–Marie Curie discovered the radioactive elements namely Polonium and Radium in 1898.
โž–For her discovery, Marie Curie won the Nobel Prize.


โœ…Radioactive Rays
โž–After long years of experiment, Ernest Rutherford along with his colleague (Hans Geiger and his student Ernest Marsden), discovered alpha rays, beta rays, and gamma rays.
โž–These rays emitted as the result of the disintegration of atoms.


โœ…Alpha (ฮฑ) Particles
โž–Alpha particles are usually composed of two protons and two neutrons, which are tightly bound together.
โž–Alpha particles are being released during radioactive decay (or alpha decay) from the nucleus radio nuclides.
โž–The alpha particles are identical to the nucleus of either normal helium atom or doubly ionized helium atom.
โž–In comparison to other particles (i.e. Gamma and Beta), alpha particles are heavy and slow. Therefore, alpha particles have very small range in the air.
โž–Because of slow speed, Alpha particles have very weak penetrating powers; these particles are even stopped by a thin paper sheet (see image given above).
โž–Because of having the double positive charge, alpha particles are highly ionizing.


โœ…Beta (ฮฒ) Particles
โž–
Beta particles are the fast moving electrons emitted by some radio nuclides during the radioactive decay (also known as beta decay).
โž–Beta particles are of much lighter weight and carry a single negative charge.
โž–Beta particles are rarely ionizing than the alpha particles.
โž–Because of having lighter weight, beta particles can travel much farther than alpha particles; however, beta particles can be stopped by several sheet of papers or one sheet of aluminum.
โž–Beta particles are negatively charged and get attracted towards positively charged particles.


โœ…Gamma (าฏ) Particles
โž–
Gamma particles are the bundle of high energy namely electromagnetic energy (photon) emitted by the radioactive elements during the radioactive decay.
โž–Among all three particles (alpha, beta, and gamma), gamma particles are the most energetic photons.
โž–Gamma particles, which are the form of electromagnetic radiation(EMR), originate from the nucleus.
โž–The wavelengths of gamma are the shortest among all three.
โž–Gamma particles have no charge and they are neutral; therefore, they are unaffected by magnetic and electric fields.


โœ…Uses of Radioactive Elements
โž–
Medical field (treatment of many diseases)
โž–Industrial process
โž–Energy production โ€“ Nuclear reactors
๐Ÿ‘17๐Ÿค—3๐Ÿ†1
๐Ÿ” ๐Ÿ…ฐ๏ธ๐Ÿ” ๐Ÿ” ๐Ÿ” ยฉ๏ธ๐Ÿ” ๐Ÿ…ฐ๏ธ๐Ÿ” ๐Ÿ” ๐Ÿ” ๐Ÿ” ๐Ÿซก

PYQ's Class 12 Physics || Atoms Previous year Questions By Arshpreet Ma'am
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Biology Class 12th Boards | 2 Marks Questios | PYQ's + MIQ's Class 12 | By SakshI Ma'am
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โ™ป๏ธ Important Scientific Laws and Theories โ™ป๏ธ
==============================

๐Ÿ”น Ohm's Law - It states that the current passing through a conductor between two points is directly proportional to the potential difference across the two points provided the physical state and temperature etc. of the conductor does not change.

๐Ÿ”น Pauli exclusion principle - It explains that no two electrons in the same atom or molecule can have the same set of quantum numbers.

๐Ÿ”น Raman effect - It is the change in wavelength that occurs when light is scattered by the atoms or molecules in a transparent medium.

๐Ÿ”น Tyndall effect - The scattering of light by very small particles suspended in a gas or liquid.

๐Ÿ”น Boyles's Law - It states that temperature remaining constant, volume of a given mass of a gas varies inversely with the pressure of the gas. Thus,
PV = K (constant), where, P = Pressure and V = Volume.

๐Ÿ”น Charles's Law - It states that pressure remaining constant, the volume of a given mass of gas increases or decreases by 1/273 part of its volume at 0 degree celsius for each degree celsius rise or fall of its temperature.

๐Ÿ”น Coulomb's Law - It states that force of attraction or repulsion between two charges is proportional to the amount of charge on both charges and inversely proportional to the square of the distance between them.

๐Ÿ”น Heisenberg principle (uncertainty principle) - It is impossible to determine with accuracy both the position and the momentum of a particle such as electron simultaneously.

๐Ÿ”น Archimede's principle - It states that a body when wholly or partially immersed in a liquid, experiences an upward thrust which is equal to the weight of the liquid displaced by it. Thus, the body appears to lose a part of its weight. This loss in weight is equal to the weight of the liquid displaced by the body.

๐Ÿ”น Aufbau principle - It states that in an unexcited atom, electrons reside in the lowest energy orbitals available to them.

๐Ÿ”น Avogadro's Law - It states that equal volumes of all gases under similar conditions of temperature and pressure contain equal number of molecules.

๐Ÿ”น Brownian motion - It is a zigzag, irregular motion exhibited by small solid particles when suspended in a liquid or gas due to irregular bombardment by the liquid or gas molecules.

๐Ÿ”น Bernoulli's principle - It states that as the speed of a moving fluid, liquid or gas, increases, the pressure within the fluid decreases. The aerodynamic lift on the wing of an aeroplane is also explained in part by this principle.

๐Ÿ”น Gay-Lussacโ€™s Law of combining volumes - Gases react together in volumes which bear simple whole number ratios to one another and also to the volumes of the products, if gaseous โ€” all the volumes being measured under similar conditions of temperature and pressure.

๐Ÿ”น Grahamโ€™s Law of Diffusion - It states that the rates of diffusion of gases are inversely proportional to the square roots of their densities under similar conditions of temperature and pressure.

๐Ÿ”น Kepler's Law - Each planet revolves round the Sun in an elliptical orbit with the Sun at one focus. The straight line joining the Sun and the planet sweeps out equal areas in equal intervals. The squares of the orbital periods of planets are proportional to the cubes of their mean distance from the Sun.

๐Ÿ”น Law of Floatation - For a body to float, the following conditions must be fulfilled: The weight of the body should be equal to the weight of the water displaced and the centre of gravity of the body and that of the liquid displaced should be in the same straight line.

๐Ÿ”น Law of conservation of energy - It states that energy can neither be created nor destroyed but it can be transformed from one form to another. Since energy cannot be created or destroyed, the amount of energy present in the universe is always remain constant.
๐Ÿ‘23๐Ÿค—4โค1๐Ÿ”ฅ1๐Ÿ‘1
The area of the figure bounded by the curve y = logex, the x-axis and the straight line x = e is ?
Anonymous Quiz
19%
5-e
41%
3+e
32%
1
8%
None of these
๐Ÿ‘3โค2๐Ÿค—2
What is the order of differential equation yโ€™โ€™ + 5yโ€™ + 6 = 0?
Anonymous Quiz
13%
a.0
25%
b.1
59%
c.2
3%
d.3
๐Ÿค”34๐Ÿคฏ16๐Ÿ˜ฑ6๐Ÿ‘5
๐Ÿ†๐Ÿ’œ๐Ÿ”ค๐Ÿ”ค 1๏ธโƒฃ๐Ÿ”  ๐Ÿ’œ๐Ÿ’œ๐Ÿ’œ๐Ÿ’œ๐Ÿ’œ๐Ÿ’œ๐Ÿ’œ๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ†

๐ŸŒด๐ŸŒด๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐Ÿ”ค๐ŸŒด๐ŸŒด


1.Which of these processes does not give off CO2?

a.Lactate fermentation
b.Aerobic respiration
c.Alcoholic fermentation
d.None of the above.

Ans.a

2.High biological oxygen demand in a water body means ________

a.Water is not polluted
b.Water is polluted
c.Waterbody contains lots of lifeforms
d.None of the above

Ans.b

3.The guts of various ruminants contain _________

a.Acidophiles
b.Halophiles
c.Methanogens
d.All of the above

Ans.c

4.Which of the following microbes are used for the commercial production of citric acid?

a.Xanthomonas citri
b.Asparagine
c.Asparagus
d.Aspergillu
s
Ans.d

5.Saccharomyces cerevisiae is used primarily for ?

a.Baking
b.Bleaching
c.Biofuel
d.None of the above

Ans.a

6.Acinetobacter baumannii is a _________

a.Decomposing bacteria
b.Pathogenic bacteria
c.Nitrogen-fixing bacteria
d.None of the above

Ans.b

7.Ethanol can be produced using __________

a.Saccharomyces cerevisiae
b.Escherichia coli
c.Pseudomonas syringae
d.None of the above

Ans.a

8.Bacillus thuringiensis is used for ?

a.Fermentation of beer
c.Biopesticide
c.Antibiotic
d.None of the above

Ans.b

9.Before antibiotics, the first commercial antibacterial available was _____

a.Penicillin
b.Prontosil
c.Azithromycin
d.None of the above

Ans.b

10.Example of a natural insect repellant

a.Citronella oil
b.Coconut oil
c.Linseed oil
d.None of the above

Ans.a

๐Ÿ…ฑ๏ธ๐Ÿ” ๐Ÿ” ๐Ÿ” ๐Ÿ” ๐Ÿ” ๐Ÿ” 
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Saccharomyces cerevisiae is used primarily for ?
Anonymous Quiz
53%
a.Baking
26%
b.Bleaching
15%
c.Biofuel
6%
d.None of the above
๐Ÿ‘11โค2๐Ÿ†2๐Ÿคฉ1
The guts of various ruminants contain _________
Anonymous Quiz
16%
a.Acidophiles
18%
b.Halophiles
48%
c.Methanogens
19%
d.All of the above
๐Ÿคฏ15๐Ÿ‘9๐Ÿค—2โค1๐Ÿ˜ฑ1
โœ…Very important points - Human Reproduction

๐ŸŒŸUterus also called womb.

๐ŸŒŸ Longest unstripped muscles of the body are found in the walls of uterus. (During pregnancy)

๐ŸŒŸ Clitoris is a homologous to the penis in the male.

๐ŸŒŸ Bartholin Glands : It is homologous to Cowper's gland of male

๐ŸŒŸ A functional mammary gland is characteristic of all female mammals.

๐ŸŒŸ The milk produced during the initial few days of lactation is called colostrum which contains antibodies (IgA) absolutely essential to develop resistance for the new-born babies.

โšก๏ธ Liberation of sperms from Sertoli cells of seminiferous tubules is called spermiation.

โšก๏ธ Liberation of sperms from testes is called semination.

โšก๏ธ Liberation of sperms from body of male is called ejaculation .

โšก๏ธ Mammalian sperms are transfered to vagina of female by the process called insemination.

โšก๏ธ In 1 ml of semen, 20 to 120 millions of sperms are present in human being.

โšก๏ธ Leydig's cells mature at 10 yrs. of age.

โšก๏ธ In humans (and most vertebrates), the first polar body does not undergo meiosis II.

โšก๏ธ The first polar body is, therefore, formed merely to get rid of unwanted chromosomes.
๐Ÿ‘21๐Ÿฅฐ1
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Session Link -
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โ˜€๏ธโ˜€๏ธ Good Morning
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Cbse big update boards 2024 admit card released ๐Ÿ”ฅ๐Ÿ”ฅ
๐Ÿ‘16โค2๐Ÿค—1
Which of the following gives the polarity of the induced emf?
Anonymous Quiz
19%
Biot-Savart Law
54%
Lenzโ€™s Law
15%
Ampereโ€™s circuital Law
11%
Flemingโ€™s right-hand Rule
๐Ÿ‘15๐Ÿ’ฏ13โค4๐Ÿค—1
Electrical Inertia is the measure of?
Anonymous Quiz
35%
Self Inductance
28%
Mutual Inductance
29%
Impedance
8%
None of the above
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