class 9th, science chapter 3, important questions

  1. What are isotopes? Give two examples.
  2. How is the valency of an atom related to its electronic configuration?
  3. Calculate the atomic number of the element whose atomic nucleus has mass number of 23 and neutron number 12.What is the symbol for this element?
  4. Nucleus of an atom has 5 protons and 6 neutrons.What would be the atomic number,the mass number,the number of electrons and the number of valency electrons per atom of this element?
  5. What valency will be shown by an element having atomic number 15?
  6. An element has atomic number 16 .How many electrons will be present in K,L and M energy shells of its atom? What will its electro-valency be?
  7. What are valence electrons? Write the number of Valency electrons present in the elements: carbon,sodium and phosphorus.
  8. Draw the electronic structure of sodium and calcium with atomic number 11 and 20 respectively.
  9. Give four differences between cathode rays and canal rays.
  10. Write the main characteristic properties of cathode rays.
  11. Define electron, proton and neutrons.
  12. What is meant by atomic number of an element? Does the atomic number of an element change when its atoms from ions? Give one example each of diatomic and triatomic molecules.
  13. An element M has atomic mass 24 and atomic number 12. How many neutrons does its atom contain? How many electrons will be present in K,L and M energy shells of its atoms ?
  14. An element has atomic number 17. How many electrons will be present in the K,L and M energy shells of the atom?What will its electro-valency be?
  15. Elements A, B, C and D have atomic numbers 11,8,1 and 17 respectively.Give the chemical formulae of the compounds formed between (i) A and D (ii) B and C.
  16. Which fundamental particle is equal in number in Mg2+ and AL3+ ions ?An atom has electronic configuration of 2,8,7

362 thoughts on “class 9th, science chapter 3, important questions”

  1. В уральских горах берут начало многие реки, которые, развиваясь и пополняясь притоками, становятся полноводными и судоходными. Ни один регион страны не может сравниться с Уралом по количеству озер, особенно это касается его южной части, которую называют «Страной озер» или более поэтично – «Голубым ожерельем России». У Алтайского края богатая история. Здесь найдено множество памятников культуры, которые рассказывают о жизни народов, населявших край в разное время. Самые древние следы присутствия человека на этой земле появились 1,5 млн лет назад. В этих местах можно увидеть скифские курганы, величественные древнетюркские каменные изваяния, наскальные рисунки и загадочные рунические письма. Люди жили здесь с глубокой древности, чему имеется немало свидетельств. Интерес ученых подстегнули относительно недавние находки погребений пазырыкской культуры: не только знаменитая мумия с татуировками «Принцесса Укок», но и конструкции в виде срубов, высокохудожественные изделия из дерева, войлока и кожи. Алтайская земля хранит еще немало секретов. Озеро Кардывач.
    https://moooga.ru/chernogoriya/perast-chernogoriya-dostoprimechatelnosti-na-karte-foto-marshrut-chto-posmotret-v-gorode-za-1-2-dnya-samostoyatelno-interesnye-mesta-turistu/ Баксанское ущелье – одно из любопытнейших и живописнейших мест Северного Кавказа. Название оно получило благодаря реке. Ущелье открывает путь в волшебный мир гор, ведь здесь пролегает дорога в Приэльбрусье. Зеленый бархат долин и полей по мере продвижения вглубь гор с каждым новым витком дороги сменяется могучими заснеженными вершинами с грозными ледниками на склонах. От всего этого великолепия у не привыкшего к горам человека захватывает дух. Бак-санское ущелье выходит прямо к подножию Эльбруса. В долинной его части климат сравним с условиями Доломитовых Альп, в горах на высоте 4000 м – настоящая Сибирь. Навалишинский каньон.

  2. ####### OPVA ########
    ULTIMATE РТНС COLLECTION
    NO PAY, PREMIUM or PAYLINK
    DOWNLOAD ALL СР FOR FREE

    Description:-> gg.gg/xtebj

    Webcams РТНС 1999-2022 FULL
    STICKAM, Skype, video_mail_ru
    Omegle, Vichatter, Interia_pl
    BlogTV, Online_ru, murclub_ru

    Complete series LS, BD, YWM
    Sibirian Mouse, St. Peterburg
    Moscow, Liluplanet, Kids Box
    Fattman, Falkovideo, Bibigon
    Paradise Birds, GoldbergVideo
    Fantasia Models, Cat Goddess
    Valya and Irisa, Tropical Cuties
    Deadpixel, PZ-magazine, BabyJ
    Home Made Model (HMM)

    Gay рthс collection: Luto
    Blue Orchid, PJK, KDV, RBV

    Nudism: Naturism in Russia
    Helios Natura, Holy Nature
    Naturist Freedom, Eurovid

    ALL studio collection: from
    Acrobatic Nymрhеts to Your
    Lоlitаs (more 100 studios)

    Collection european, asian,
    latin and ebony girls (all
    the Internet video) > 4Tb

    Rurikon Lоli library 171.4Gb
    manga, game, anime, 3D

    This and much more here:
    or –> gg.gg/ygjj7
    or –> url.pm/QfkyU
    or –> u2b.eu/ua
    or –> v.ht/LEYc
    or –> cutt.us/jKbHA
    or –> gg.gg/ntwgr
    or –> v.ht/kIy2
    or –> gurl.pro/k6ftqd
    or –> gg.gg/ntwhd

    ###### Caution! ######
    ALL premium big parts rar
    (mix.part01..) or huge
    archives – scam. Paylinks
    (bit_ly lmy_de aww_su and
    other) – virus. Be careful.
    —————–
    —————–
    000A000083

  3. If your monogram’s battery can be removed, it could be a all right create to [url=https://www.vapelargest.com/]Vape Store[/url] hire skilled in an mark-up battery and to screen it with you at all times. Nothing is more frustrating than starting to vape, solitary to recognize your put on paper’s battery died and there is no sanity [url=https://www.vapejuice.biz/]vape juice[/url] due to the fact that you to accuse it at the moment. Beginners power be too agitated less the multitudinous peculiar flavours of [url=https://www.vapeperson.com/]vape shop[/url] e-juice at to pick equitable an idiosyncratic and poke to it. This practice, your vape commit to review velleity at any time be fully serviceable, whether you are diggings, at accomplishment, or on the go. You should not disabuse admit your vape corral pen [url=https://www.vapedance.com/]Best Vape[/url] animation when you are not using it. The misinterpret that heats the e-juice to meet smog will after all floor its heat to other parts of the contrivance, and your lawyer could swell anxious if you misuse your vape essay instrument on too long. But after some metre, perhaps you pass repossess your white-headed house-servant nature and solely vape this one. Your vape promise to paper approve not decrease if you think of it in your auto [url=https://www.vapestores.biz/]Vape Store[/url] due to the fact that hours during a least keen summer day. But the e-juice in the vape tank could split, and that wouldn’t be a [url=https://www.vapebegin.com/]Vape Store[/url] principled id俥 fixe quest of your widget or an eye to whatever plane superficially it’s placed on. Be methodical to sidestep exposing your vape scratch to draconian temperatures and too vigorous temperature changes.

  4. Галасеина Астра

    [url=https://helpdesk.hostia.de/ticket/ticket/2824-%D0%BE%D0%B1%D0%BE%D1%80%D1%83%D0%B4%D0%BE%D0%B2%D0%B0%D0%BD%D0%B8%D0%B5-%D1%81%D1%82%D0%B0%D0%BD%D0%BE%D0%BA-%D0%B4%D0%BE%D0%B2%D0%BE%D0%B4%D0%BE%D1%87%D0%BD%D1%8B%D0%B9/?auth=c3d5c911f247615b3a09fc0ac5980ea6b4d3a8f6]Оборудование, станок доводочный[/url]
    [url=http://jazzmarketing.de/hallo-welt#comment-3728]Оборудование, кпо[/url]
    c4a2433
    [url=https://images.google.co.je/url?q=https://mirprom.com/annoucement/102290]https://images.google.co.je/url?q=https://mirprom.com/annoucement/102290[/url]
    [url=http://www.googleadservices.com/url?q=https://mirprom.com/annoucement/102357]http://www.googleadservices.com/url?q=https://mirprom.com/annoucement/102357[/url]
    [url=http://google.co.il/url?q=https://mirprom.com/annoucement/102355]http://google.co.il/url?q=https://mirprom.com/annoucement/102355[/url]
    [url=https://google.iq/url?q=https://mirprom.com/annoucement/102264]https://google.iq/url?q=https://mirprom.com/annoucement/102264[/url]
    [url=https://google.ae/url?q=https://mirprom.com/annoucement/102279]https://google.ae/url?q=https://mirprom.com/annoucement/102279[/url]
    [url=https://maps.google.as/url?q=https://mirprom.com/annoucement/102333]https://maps.google.as/url?q=https://mirprom.com/annoucement/102333[/url]
    [url=https://images.google.com.bn/url?q=https://mirprom.com/annoucement/102320]https://images.google.com.bn/url?q=https://mirprom.com/annoucement/102320[/url]
    [url=http://images.google.st/url?q=https://mirprom.com/annoucement/102361]http://images.google.st/url?q=https://mirprom.com/annoucement/102361[/url]
    [url=https://images.google.co.ls/url?q=https://mirprom.com/annoucement/102310]https://images.google.co.ls/url?q=https://mirprom.com/annoucement/102310[/url]
    [url=http://www.google.co.nz/url?q=https://mirprom.com/annoucement/102375]http://www.google.co.nz/url?q=https://mirprom.com/annoucement/102375[/url]

    [url=http://www.jewellerynews.ru/process/gourl2.html?url=https://mirprom.com/annoucement]http://www.jewellerynews.ru/process/gourl2.html?url=https://mirprom.com/annoucement[/url]
    [url=https://loopbaan.dezorggroep.nl/redirect.php?from=mirprom.com/annoucement]https://loopbaan.dezorggroep.nl/redirect.php?from=mirprom.com/annoucement[/url]
    [url=http://www.theamericanmuslim.org/tam.php?URL=mirprom.com/annoucement]http://www.theamericanmuslim.org/tam.php?URL=mirprom.com/annoucement[/url]
    [url=http://profiwm.com/all/str.php?URL=https://mirprom.com/annoucement]http://profiwm.com/all/str.php?URL=https://mirprom.com/annoucement[/url]
    [url=http://localhoneyfinder.org/facebook.php?URL=https://mirprom.com/annoucement]http://localhoneyfinder.org/facebook.php?URL=https://mirprom.com/annoucement[/url]
    [url=http://forum.ahigh.ru/away.htm?link=https://mirprom.com/annoucement]http://forum.ahigh.ru/away.htm?link=https://mirprom.com/annoucement[/url]
    [url=http://link.fob580.com/?url=https://mirprom.com/annoucement]http://link.fob580.com/?url=https://mirprom.com/annoucement[/url]
    [url=http://bramka.proxy.net.pl/index.php?q=https://mirprom.com/annoucement]http://bramka.proxy.net.pl/index.php?q=https://mirprom.com/annoucement[/url]
    [url=https://forum-en.gw2archive.eu/external?l=https://mirprom.com/annoucement]https://forum-en.gw2archive.eu/external?l=https://mirprom.com/annoucement[/url]
    [url=http://cssdrive.com/?URL=mirprom.com/annoucement]http://cssdrive.com/?URL=mirprom.com/annoucement[/url]

    [url=http://www.google.com.np/url?q=https://www.realbrest.by/interesnye-obzory/vsego-po-nemnogu/novosti-ot-polzovatelei/vozmozhnosti-sovremennyh-internet-ploschadok-v-sfere-promyshlennogo-oborudovanijaa.html]http://www.google.com.np/url?q=https://www.realbrest.by/interesnye-obzory/vsego-po-nemnogu/novosti-ot-polzovatelei/vozmozhnosti-sovremennyh-internet-ploschadok-v-sfere-promyshlennogo-oborudovanijaa.html[/url]
    [url=http://google.com.kh/url?q=https://beton-area.com/%d0%b2%d1%8b%d0%b1%d1%80%d0%b0%d1%82%d1%8c-%d1%80%d0%b5%d0%b7%d1%8c%d0%b1%d0%be%d0%be%d0%b1%d1%80%d0%b0%d0%b1%d0%b0%d1%82%d1%8b%d0%b2%d0%b0%d1%8e%d1%89%d0%b8%d0%b9-%d1%81%d1%82%]http://google.com.kh/url?q=https://beton-area.com/%d0%b2%d1%8b%d0%b1%d1%80%d0%b0%d1%82%d1%8c-%d1%80%d0%b5%d0%b7%d1%8c%d0%b1%d0%be%d0%be%d0%b1%d1%80%d0%b0%d0%b1%d0%b0%d1%82%d1%8b%d0%b2%d0%b0%d1%8e%d1%89%d0%b8%d0%b9-%d1%81%d1%82%[/url]
    [url=https://images.google.co.zw/url?q=https://beton-area.com/%d0%b2%d1%8b%d0%b1%d1%80%d0%b0%d1%82%d1%8c-%d1%80%d0%b5%d0%b7%d1%8c%d0%b1%d0%be%d0%be%d0%b1%d1%80%d0%b0%d0%b1%d0%b0%d1%82%d1%8b%d0%b2%d0%b0%d1%8e%d1%89%d0%b8%d0%b9-%d1%81%d1%82%]https://images.google.co.zw/url?q=https://beton-area.com/%d0%b2%d1%8b%d0%b1%d1%80%d0%b0%d1%82%d1%8c-%d1%80%d0%b5%d0%b7%d1%8c%d0%b1%d0%be%d0%be%d0%b1%d1%80%d0%b0%d0%b1%d0%b0%d1%82%d1%8b%d0%b2%d0%b0%d1%8e%d1%89%d0%b8%d0%b9-%d1%81%d1%82%[/url]
    [url=https://images.google.com.mm/url?q=https://electricavdome.ru/kak-vybrat-metallorezhushhie-stanki.html]https://images.google.com.mm/url?q=https://electricavdome.ru/kak-vybrat-metallorezhushhie-stanki.html[/url]
    [url=https://images.google.be/url?q=http://okvsk.ru/novosti/19920-pokupka-sozh-masla-i-sistemy.html]https://images.google.be/url?q=http://okvsk.ru/novosti/19920-pokupka-sozh-masla-i-sistemy.html[/url]
    [url=https://google.tg/url?q=https://www.azovpromstal.com/article/one/id/5567]https://google.tg/url?q=https://www.azovpromstal.com/article/one/id/5567[/url]
    [url=http://www.googleadservices.com/url?q=https://expert-byt.ru/raznovidnosti-mikroskopov/]http://www.googleadservices.com/url?q=https://expert-byt.ru/raznovidnosti-mikroskopov/[/url]
    [url=https://images.google.sh/url?q=https://odnastroyka.ru/raznovidnosti-metallorezhushhih-stankov/]https://images.google.sh/url?q=https://odnastroyka.ru/raznovidnosti-metallorezhushhih-stankov/[/url]
    [url=https://www.google.sm/url?q=http://racechrono.ru/novosti/25072-materialy-i-komplektuyuschie-dlya-svarki-vidy-elektrodov.html]https://www.google.sm/url?q=http://racechrono.ru/novosti/25072-materialy-i-komplektuyuschie-dlya-svarki-vidy-elektrodov.html[/url]
    [url=http://images.google.bf/url?q=https://region35.ru/sistema-ucheta-gaza-na-gns-i-agzs.htm]http://images.google.bf/url?q=https://region35.ru/sistema-ucheta-gaza-na-gns-i-agzs.htm[/url]

    [url=https://google.sc/url?q=https://mirprom.com/]https://google.sc/url?q=https://mirprom.com/[/url]
    [url=http://maps.google.pn/url?q=https://mirprom.com/]http://maps.google.pn/url?q=https://mirprom.com/[/url]
    [url=http://www.google.ba/url?q=https://mirprom.com/]http://www.google.ba/url?q=https://mirprom.com/[/url]
    [url=https://images.google.bi/url?q=https://mirprom.com/]https://images.google.bi/url?q=https://mirprom.com/[/url]
    [url=http://google.si/url?q=https://mirprom.com/]http://google.si/url?q=https://mirprom.com/[/url]
    [url=http://maps.google.co.kr/url?q=https://mirprom.com/]http://maps.google.co.kr/url?q=https://mirprom.com/[/url]
    [url=https://images.google.to/url?q=https://mirprom.com/]https://images.google.to/url?q=https://mirprom.com/[/url]
    [url=https://images.google.off.ai/url?q=https://mirprom.com/]https://images.google.off.ai/url?q=https://mirprom.com/[/url]
    [url=https://images.google.at/url?q=https://mirprom.com/]https://images.google.at/url?q=https://mirprom.com/[/url]
    [url=https://maps.google.ca/url?q=https://mirprom.com/]https://maps.google.ca/url?q=https://mirprom.com/[/url]

    [url=https://domavlad.ru/stati/vidy-sovremennoj-rezki-metalla.html]виды современной резки металла[/url]
    [url=https://www.steelland.ru/press/3082.html]спирали из нихрома для электрических печей[/url]
    [url=https://aragoncom.ru/zernouborochnaya/chto-takoe-elektronno-luchevaya-svarka.html]что такое электронно-лучевая сварка?[/url]

    [url=https://mogu-id.com/hello-world#comment-5441]Оборудование, академии[/url]
    [url=https://gardensport.org/how-to-transform-your-lawn-into-a-food-forest/#comment-100989]Оборудование, электро-химический станок[/url]
    [url=https://helpdesk.hostia.de/ticket/ticket/2824-%D0%BE%D0%B1%D0%BE%D1%80%D1%83%D0%B4%D0%BE%D0%B2%D0%B0%D0%BD%D0%B8%D0%B5-%D1%81%D1%82%D0%B0%D0%BD%D0%BE%D0%BA-%D0%B4%D0%BE%D0%B2%D0%BE%D0%B4%D0%BE%D1%87%D0%BD%D1%8B%D0%B9/?auth=c3d5c911f247615b3a09fc0ac5980ea6b4d3a8f6]Оборудование, станок доводочный[/url]

    Что можете посоветовать?

  5. [url=https://world-crypt-fr.site]cour crypto monnaie[/url]

    As in numerous countries, the at the start attempts to regulate cryptocurrencies in France occurred in the technique of detecting financial crimes. In its 2011 annual record, Tracfin (the French fiscal aptitude unit for combating fiscal fake, money laundering and the financing of verboten activities) was the principal density to upon Bitcoin.
    crypto monnaie cours

  6. I appreciate, lead to I discovered just what I used to be looking for.You’ve ended my four day lengthy hunt! God Bless you man.Have a nice day. Bye

  7. I am very happy to read this. This is the type of manual that needs to be given and not the accidental misinformation that’s at the other blogs. Appreciate your sharing this greatest doc.

  8. Hi there! I just wanted to ask if you ever have any issues with hackers? My last blog (wordpress) was hacked and I ended up losing months of hard work due to no data backup. Do you have any solutions to stop hackers?

  9. Hello There. I discovered your blog the use of msn. That is an extremely well written article. I’ll make sure to bookmark it and come back to learn more of your helpful information. Thanks for the post. I’ll definitely return.

Leave a Comment

Your email address will not be published.