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    • Posted by Priyal Gupta 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 1 answers

    ☆ Pranal Rewatkar ☆ 4 years, 10 months ago

    A SUBSTANCE IS A PURE SINGLE FORM OF MATTER

    2Thank You

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    • Posted by Rohan Sinha 4 years, 6 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Sia ? 4 years, 6 months ago

    m = 70 kg
    v = 9 kmph = 9 * 5/18 = 2.5 m/s
    u = 18 kmph = 18 * 5/18 = 5 m/s
    Work done  = change in kinetic energy
    = initial KE - final KE
    = 1/2 m u² - 1/2 m v²
    = 1/2 * 70 * 5² - 1/2 * 70 * 2.5²
    = 875 J - 218.75 J  = 656.25  J
    The speed has come down to half its value.  But the Kinetic energy becomes 218.75/875 = 1/4 th of inital KE.

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    • Posted by Mehul Jain 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 4 answers

    Sanjana Parmar 4 years, 10 months ago

    Yes

    0Thank You

    Shriram J 4 years, 10 months ago

    Yes absolutely it is a cell organelles as it produce proteins

    0Thank You

    Priyal Gupta 4 years, 10 months ago

    Yes ribosomes are a cell organelle. They are attached to the rough endoplasmic reticulum in the cell

    0Thank You

    Bagadhi Tanuj Chowdary 4 years, 10 months ago

    Yes

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    • Posted by Smit Pandya 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 2 answers

    Rimjhim Goswami 4 years, 10 months ago

    Phloem parenchyma is one of the types of phloem cells it help in food storage

    0Thank You

    Ayush Garg 4 years, 10 months ago

    It's a part of phloem which is a part of animals tissue

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    • Posted by Nisha Murali 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 5 answers

    Sanjana Parmar 4 years, 10 months ago

    Triatomic molecule

    0Thank You

    Tejash Jha 4 years, 10 months ago

    Triatomic

    0Thank You

    Saloni Harinkhede 4 years, 10 months ago

    Triatomic

    0Thank You

    Kalash Tulsi Pareek 4 years, 10 months ago

    Triatomic

    1Thank You

    Priyash Raj 4 years, 10 months ago

    Triatomic

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    • Posted by Hasina Mandar 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Priyash Raj 4 years, 10 months ago

    Yes

    1Thank You

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    • Posted by Manvendra Parmar 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Priyash Raj 4 years, 10 months ago

    No. Of molecule = no. Of mole × Avagardo Constant

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    • Posted by Khusi Pradhan 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Akash Kumar 4 years, 10 months ago

    A push and pull an object is called force AND The product of mass and velocity of an object is called momentum

    1Thank You

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    • Posted by Jagyaseni Behera 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 2 answers

    Baalveer Returns 4 years, 10 months ago

    M×G×H where m is mass g is gravitational force h is height

    0Thank You

    Priyash Raj 4 years, 10 months ago

    P. E = M×G×H where m is mass g is gravitational force h is height

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    • Posted by Nihal Rajak 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 2 answers

    Mohit Tanwar 4 years, 10 months ago

    Its depends on Joseph

    0Thank You

    Anushk Ramesh 4 years, 10 months ago

    Yo bro

    0Thank You

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    • Posted by Utkarsh Chaturvedi 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 2 answers

    Saloni Harinkhede 4 years, 10 months ago

    Because the simlar charge reepal each other

    0Thank You

    Priyash Raj 4 years, 10 months ago

    Because the simlar charge reepal each other

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    • Posted by Asma Raza 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 0 answers
    ANSWER

    • Posted by Abhijeet Tiwari 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 4 answers

    Ankush Ranjan 4 years, 10 months ago

    Asthama, chicken pox, cold etc

    1Thank You

    Priyash Raj 4 years, 10 months ago

    Corona, chicken pox

    0Thank You

    Mohit Tanwar 4 years, 10 months ago

    Covid -19 , cold

    1Thank You

    Pragati Yadav 4 years, 10 months ago

    Asthama , covid-19

    3Thank You

    ANSWER

    • Posted by Swapnil Singh 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 2 answers

    Ayushi Suryavanshi 4 years, 10 months ago

    Any substance is said to be pure if and only if it is made up a single type of particles means all the particles of that substance should be of same chemical nature. For example water,sugar,salt, sodium,tin, etc.

    1Thank You

    Rishika Dhindwal 4 years, 10 months ago

    A substance is a pure single form of matter . It cannot separated into other kinds of matter by any physical process.

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    • Posted by Palak Goyal 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Priyal Gupta 4 years, 10 months ago

    Peroxisomes are found in the cytoplasm of a eukaryotic cell

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    • Posted by Arpit Srivastav 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Palak Goyal 4 years, 10 months ago

    Kinetic energy

    1Thank You

    ANSWER

    • Posted by Varsha Gemnani 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 0 answers
    ANSWER

    • Posted by Nisha Murali 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 2 answers

    Ankush Ranjan 4 years, 10 months ago

    Gravitational force

    0Thank You

    Rishika Dhindwal 4 years, 10 months ago

    Gravity

    1Thank You

    ANSWER

    • Posted by Sachi Khushalani 4 years, 7 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Sia ? 4 years, 7 months ago

    “Wishing you a day filled with happiness and a year filled with joy. Happy birthday!” “Sending you smiles for every moment of your special day…Have a wonderful time and a very happy birthday!” “Hope your special day brings you all that your heart desires!

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    • Posted by Manish Kumar 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 0 answers
    ANSWER

    • Posted by Aditi Sinha 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Kajal Yadav 4 years, 10 months ago

    This content has been hidden. One or more users have flagged this content as inappropriate. Once content is flagged, it is hidden from users and is reviewed by myCBSEguide team against our Community Guidelines. If content is found in violation, the user posting this content will be banned for 30 days from using Homework help section. Suspended users will receive error while adding question or answer. Question comments have also been disabled. Read community guidelines at https://mycbseguide.com/community-guidelines.html Few rules to keep homework help section safe, clean and informative. Don't post personal information, mobile numbers and other details. Don't use this platform for chatting, social networking and making friends. This platform is meant only for asking subject specific and study related questions. Be nice and polite and avoid rude and abusive language. Avoid inappropriate language and attention, vulgar terms and anything sexually suggestive. Avoid harassment and bullying. Ask specific question which are clear and concise. Remember the goal of this website is to share knowledge and learn from each other. Ask questions and help others by answering questions.

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    • Posted by Prachi Verma 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Akshat Holland Minettee 4 years, 10 months ago

    According to Bhor's Model of an Atom - 1) Only some special orbits called discrete orbits are allowed in an atom. 2) While revolving around the discrete orbits electrons do not radiate energy. 3) The shells or orbits in an atom are known as energy levels and are named as n= K, L, M, N and so on or 1,2,3,4...

    1Thank You

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    • Posted by Bhupesh Yadav 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 2 answers

    Kripa Daga 4 years, 10 months ago

    •Go in science column •Select chapter atoms and moleclues •select cbse revision notes •click on the row •scroll down and you have your notes •thanks

    0Thank You

    Kripa Daga 4 years, 10 months ago

    Laws of Chemical Combination Limitation of “Law of definite proportion” This law does not hold good when the compound is obtained by using different isotopes of the combining elements. 2. John Daltons Atomic Theory Using his theory, Dalton rationalized the various laws of chemical combination which were in existence at that time. However, he assumed that the simplest compound of two elements must be binary. 3. Atoms, Molecules, Ions & Chemical Formula Atom An atom is the smallest particle of an element which can take part in a chemical reaction. It may or may not exist freely. Each atom of an element shows all the properties of the element. Molecule The smallest particle of matter (element or compound) which can exist in a free state. The properties of a substance are the properties of its molecules. MOLECULES OF ELEMENT : The molecules of an element are constituted by the same type of atoms. MOLECULES OF COMPOUND: Atoms of different elements join together in definite proportions to form molecules of compounds. (hetero atomic molecules) ATOMICITY: The number of atoms contained in a molecule of a substance (element or compound) is called its atomic Element Formula Atomicity Ozone O3 3 Phosphorus P4 4 Sulphur S8 8 Oxygen O2 2 Based upon atomicity molecules can be classified as follows. Monoatomic molecules: Noble gases helium, neon and argon exist as He Ne and Ar respectively. Diatomic molecules: Triatomic molecules: SYMBOLS The abbreviation used to represent an element is generally the first letter in capital of the English name of element. Oxygen O Nitrogen N When the names of two or more elements begin with the same initial letter, the initial letter followed by the letter appearing later in the name is used to symbolize the element Barium Ba Bismuth Bi Symbols of some elements are derived from their Latin names ELEMENT LATIN NAME SYMBOL Sodium Natrium Na Copper Cuprum Cu Potassium Kalium K Iron Ferrum Fe Mercury Hydragyrum Hg Tungsten Wolfram W Polyatomic Ion : A group of atoms carrying a charge is as polyatomic ion. Eg. Valency : The number of electrons which an atom can lose , gain or share to form a bond. OR It is the combining capacity of an atom of the element. Chemical Formula : A chemical formula is a short method of representing chemical elements and compounds. Writing a Chemical Formula -CRISS-CROSS rule RULES > All subscripts must be reduced to lowest term (except for molecular or Examples CATION ANION FORMULA NAME Aluminium sulphate Ca Calcium bicarbonate Ammonium chloride Sodium carbonate Magnesium hydroxide Sodium phosphate 4. Mole Concept The mole (mol) is the amount of a substance that contains as many elementary entities as there are atoms in exactly 12.00 grams of The Avogadro constant is named after the early nineteenth century Italian scientist Amedeo Avogadro. GRAM MOLECULAR MASS Gram molecular mass is the mass in grams of one mole of a molecular substance. Ex: The molecular mass of is 28, so the gram molecular mass of is 28 g. ATOMIC MASS UNIT An atomic mass unit or amu is one twelfth of the mass of an unbound atom of carbon-12. It is a unit of mass used to express atomic masses and molecular masses. Also Known As: Unified Atomic Mass Unit (u). MOLECULAR MASS : A number equal to the sum of the atomic masses of the atoms in a molecule. The molecular mass gives the mass of a molecule relative to that of the 12 C atom, which is taken to have a mass of 12. Examples: The molecular mass of is approximately 30 or . Therefore the molecule is about 2.5 times as heavy as the 12C atom or about the same mass as the NO atom with a molecular mass of 30 or (14 +16). 5. Molar Mass & Avogadro Constant

    2Thank You

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    • Posted by Divyanshi Mahajan 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Arpit Srivastav 4 years, 10 months ago

    Energy neither be created nor be destroyed only change one form to another.

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    • Posted by Jagyaseni Behera 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 2 answers

    Harsh Gautam 4 years, 10 months ago

    29.5306 same i also searched it

    0Thank You

    Moksh Yadav 4 years, 10 months ago

    29.5306.. I searched it in google

    0Thank You

    ANSWER

    • Posted by Sahil Naik 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Veer Singh 4 years, 10 months ago

    A force is an effort that changes the state of an object at rest or motion. It can change an object's direction and velocity. Force can also change the shape of an object.

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    • Posted by Lavesh Sharma 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Chirag .S 4 years, 10 months ago

    Good

    0Thank You

    ANSWER

    • Posted by Pushti Nadkarni 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Hãrjåß Käûr 4 years, 10 months ago

    By evaporation or distillation

    0Thank You

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    • Posted by Anjeev Shukla 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Ashu Ashu 4 years, 10 months ago

    My q

    0Thank You

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    • Posted by Praful 7609 4 years, 10 months ago

    CBSE > Class 09 > Science
    • 5 answers

    Nidhi Kaurav 4 years, 10 months ago

    Science ☺️

    1Thank You

    Saloni Dixit 4 years, 10 months ago

    Maths

    1Thank You

    Muskan Malviya 4 years, 10 months ago

    Hindi

    1Thank You

    Lucky Lion 4 years, 10 months ago

    Maths

    0Thank You

    Abhinav Patil 4 years, 10 months ago

    WASHINGTON SUNDAR ;)

    0Thank You

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