This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Write a name of an element having variable valency. |
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Answer» Answer: List of elements having variable valency Explanation: Iron : → ferrous - Fe 2+ → FERRIC - Fe 3+ Copper : → cuprous - Cu + → CUPRIC - Cu 2+ Mercury. → mercurous - Hg + → MERCURIC - Hg 2+ Gold. → aurous - Au + → AURIC - Au 3+ Silver. → argentous - Ag + → ARGENTIC - Ag 2+ Lead. → plumbous - Pb 2+ → plumbic - Pb 4+ Platinum. → platinous - Pt 2+ → platinic - Pt 4+ Tin. |
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| 2. |
Question 1:The fraction of thermally excited atoms inFlame photometry is determined byequation |
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Answer» Answer: FLAME Emission Spectrophotometry Flame emission spectrophotometry is based on the characteristic emission of light by atoms of many metallic elements when GIVEN sufficient energy, such as that supplied by a hot flame. The wavelength to be used for the measurement of an element depends on the selection of a line of sufficient intensity to provide adequate sensitivity and freedom from other interfering lines at or near the selected wavelength. For example, lithium produces a red, sodium a yellow, POTASSIUM a violet, RUBIDIUM a red, and magnesium a blue color in a flame. These colors are characteristic of the metal atoms that are PRESENT as cations in solution. Under constant and controlled conditions, the light intensity of the characteristic wavelength produced by each of the atoms is directly proportional to the number of atoms that are emitting energy, which in turn is directly proportional to the concentration of the substance of interest in the sample. Although this technique once was used for the analysis of sodium, potassium, and lithium in body fluids, it has been replaced largely by electrochemical techniques. |
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| 3. |
Discuss the formation of covalent bonds in molecules ofii. Ethylene |
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Answer» Answer: How many covalent bonds are there in a molecule of ethene? Ad by OPPO Mobile India Is the Oppo F17 Pro the sleekest phone of 2020? OPPO F17 Pro is the sleekest phone of the year in its CATEGORY. BOASTING of a 7.48mm ultra-thin and 164g ultra-lightweight body, Continue reading 25 Answers  Alistair Garratt, former Looking for Work Answered March 20, 2017 Originally Answered: How many covalent bonds are there in a molecule of ethene ? In ethene, C2H4, THREE of the four electrons in the outer shell (2s2, 2p2) of each of the carbon atoms (1s2, 2s2,2p2) are sp2 hybridized, which RESULTS in one remaining outer 2p-orbital electron. The three sp2-hybridized electrons of each C-atom form three planar sigma-covalent bonds. Per ethene molecule, four of these sp2-hybridized orbitals (six in total as we have two C-atoms) form covalent sigma-bonds with the 1s electron of each hydrogen atom (4 H-atoms for two C-atoms) while the two remaining sp2 orbitals form a sigma bond connecting the two C-atoms. Explanation: Here is your answer Hope it was helpful |
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| 4. |
Question 7 :The ratio -dl/dc gives the rate of decreaseof ------------- of radiation with concentrationof absorbing medium. |
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Answer» Explanation: QUESTION 7 : The ratio -dl/dc gives the rate of decrease of ------------- of radiation with concentration of absorbing medium. Hold on, our servers are SWAMPED. WAIT for your answer to fully load. Answer:
Explanation: Question 7 : The ratio -dl/dc gives the rate of decrease of ------------- of radiation with concentration of absorbing medium. |
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| 5. |
what is a amount of heat to be supplied to a heat engine working between 95 °C and 15 °C.if it has to do a work of 850J? |
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Answer» TI is a good day at Work and SCHOOL is over the place where I am COMING now or later tonight if I don't WANT you so bad that I'm going to be a good day today with my family |
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| 6. |
CH3-CHBr-CCliodine-CH2-Hname this compound by IUPAC rules ???plzzzzz...❤✔✅ |
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| 7. |
Question 6:mixture provides highest flametemperature. |
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Answer» Explanation: Common FLAME temperatures The closest will be the hottest PART of a flame, where the COMBUSTION REACTION is most efficient. This also assumes complete combustion (e.g. perfectly balanced, non-smokey, USUALLY bluish flame). |
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| 8. |
Q. 18 Suggest a suitable method to separate Two volatile components withappreciable difference in boiling points.Your answer |
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Answer» Explanation: Method Simple DISTILLATION can be used to separate TWO volatile components with appreciable difference in boiling points. (c) Example MIXTURE of mustard OIL and water. Method Separating runnel is used to separate a mixture of immiscible liquids. |
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| 9. |
Find the total number of moles present in3 kg of ammonium nitrate? |
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Answer» Answer: 0.0375 moles Explanation: calculate no. of moles by formula MASS/MOLAR mass molar mass of ammonium NITRATE =80u ,GIVEN mass is 3kg 3/80 = 0.0375 |
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| 10. |
Discuss the formation of covalent bonds in molecules ofi. Ammoniaii. Ethyleneiii. Carbon dioxide. |
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Answer» In ammonia (NH3), the nitrogen atom forms THREE covalent BONDS; one pair of ... Figure 2-3. In an ethylene MOLECULE, the carbon atoms are connected by a DOUBLE |
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| 11. |
3.) Deline Moderan periodic law and discuss the differentblocks in the modem periodic table. |
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Answer» modern periodic law is is the physical and chemical properties of an element are periodic function of its atomic number. Blocks: wherever the valence electron is present will be defined as the block of an element. Ex. S block which contains two GROUPS that is is alkali metal and Alkali metal group. with max 2 valence electron in it's LAST shell. P block which contains group 13 to 18 D block that is TRANSITION elements F block that is inner transition metals |
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| 12. |
6.What will be the external pressure at which watermay boil at 120°C?A. 1489 mm of Hg B. 790 mm of HgC. 700 mm of Hg D. 100 mm of Hg |
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Answer» Explanation: sorry |
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| 13. |
Na2o2 is used in the reaction that effect roll is known as..... |
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Answer» SODIUM peroxide Na2O2 Explanation: MARK it as BRAINLIEST PLZ |
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| 14. |
Calculate the ratio of atoms present in 5 gram of magnesium and 5 gram of iron |
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Answer» the WEIGHT of the magnesium is 4gram and atomic MASS is 24 so number of atom =no.of.moles * AVOGADRO number. SIMILAR for iron so it is ratio is 4/24 * 56/4. |
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| 15. |
18.5 why hydroxidee ions and bicarbonate ionscannot be. mixtogether |
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Answer» The possibility of OH-and HCO3- ions TOGETHER is ruled out because they COMBINE instantaneously to form CO32- ions. Thus OH-and HCO3- ions cannot exist together in water and hence can be concluded that all the three OH- , HCO3- ,CO32 ions cannot exist together [7,8]. Explanation: |
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| 16. |
If An element formsan oxide A2O3 which is acidic in nature Identify Aas a metal or nonnon metal. Justify |
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Answer» Answer: NON Metal. Explanation: GENERALLY non metals FORMS acidic oxides and metals form basic oxides. Eg:- MgO2,CaO2 etc are basic oxides , where Mg n Ca are metals. BO3(oxide of boron),NO3(oxide of nitrogen) etc are acidic oxides , where B and N are non metals. EXEPTIONS:- AlO3(oxide of ALUMINIUM), GaO3(oxide of galium) ,PbO n PbO2(oxides of lead), SNO2 n SnO( oxides of tin) are all amphoteric in nature. |
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| 17. |
And plz explain it |
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Answer» Formal Letter:- A letter which is GIVEN to MANAGER, principal etc. or to an office is called formal letter. Format:- \BEGIN{gathered}\begin{gathered}\boxed{\boxed{\begin{minipage}{5 cm}\sf{Sender's ADDRESS} \\ \\ \sf{Receiver's Address} \\ \\ \sf{Date}\\ \\ \sf{Salutation,}\\ \sf{.....Body.....}\\ \sf{..........}\\ \\ \sf{Complementary close}\\ \sf{Signature of sender}\end{minipage}}}\end{gathered}\end{gathered} INFORMAL Letter:- Letter given to close people -Relatives or friends. Format:- \begin{gathered}\begin{gathered}\boxed{\boxed{\begin{minipage}{5 cm} \sf{Sender's Address} \\ \\ \sf{Date} \\ \\ \sf{Salutation,}\\ \sf{.....Body.....}\\ \sf{..........}\\ \\ \sf{Complementary close}\\ \sf{Signature of sender}\end{minipage}}}\end{gathered}\end{gathered} |
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| 18. |
Question 10of the following element can not bedetected and estimated by flamephotometric technique.sodiumMagnesiumpotassiumoxygen |
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| 19. |
GURAV OMKAR HEMANTQuestion 1 :The fraction of thermally excited atoms inFlame photometry is determined byequation.Boltzmann distribution |
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Answer» Answer: Flame EMISSION Spectrophotometry Flame emission spectrophotometry is based on the characteristic emission of light by atoms of many metallic elements when given sufficient energy, such as that supplied by a hot flame. The wavelength to be used for the measurement of an element depends on the selection of a line of sufficient intensity to provide adequate sensitivity and freedom from other interfering lines at or near the selected wavelength. For example, lithium produces a red, sodium a YELLOW, potassium a violet, rubidium a red, and magnesium a blue color in a flame. These colors are characteristic of the metal atoms that are present as cations in solution. Under CONSTANT and controlled conditions, the light intensity of the characteristic wavelength produced by each of the atoms is directly proportional to the number of atoms that are emitting energy, which in turn is directly proportional to the concentration of the SUBSTANCE of interest in the sample. Although this technique once was used for the analysis of sodium, potassium, and lithium in body fluids, it has been replaced largely by electrochemical TECHNIQUES |
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| 20. |
The addition of solid sodium carbonate to pure water causes__________ * |
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Answer» Answer: An increase in ph Explanation: SODIUM Carbonate is a salt of carbonic acid with an alkalinizing PROPERTY. When dissolved in water, sodium carbonate FORMS carbonic acid and sodium hydroxide. 2Na++CO32−+H2O⇌HCO3−+OH−+2Na+ You can see that the reaction produces OH− IONS and thus the solution becomes alkaline. The pH will increase. have a great DAY.. |
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| 21. |
Evaporation differs from boiling.ExplainPlease help me to solve this chemistry question answer |
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Answer» Answer: I HOPE this Ur answer and it is helps U Explanation: PLS MARK as BRAINLIEST |
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| 22. |
Pragya tested the solubility of three different substances at different temperaturesand collected the data as given below (results are given in the following table, asgrams of a substance dissolved in 100 grams of water to form a saturated solution).Substance dissolvedTemperature in K283293313333353SolubilityPotassium nitrate213262106167Sodium chloride36363737Potassium chloride36 35 243540465437415566Ammonium chlorideWhat mass of potassium nitrate would be needed to produce a saturated solution of potassium nitrate in 50 grams of water313k |
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| 23. |
According to the structure, the Cl atoms of bleachingpowder have oxidation numbersसंरचना के अनुसार विरंजक चूर्ण में C| परमाणुओं के ऑक्सीकरणअंक हैंA0,0B0, -1+1, -1D0, +1 |
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Answer» Answer: d Explanation: n TRIANGLE,AB=AC, AD PERPENDICULAR to BC. Prove AD bisect angle A and side BC |
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| 24. |
Write a experiment of effect of heat an ice with aim, apparatus, observation and conlusion |
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Answer» Answer: Explanation: the ice will convert into aim please select the answer as brainlest answer we will observe that ice can be converted into aim |
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| 25. |
Khushi Kuch bolo yarr |
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Answer» cnncnfnfnfnfnfnnfnfnnffhfjhffjffhfuv rebddrb |
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| 26. |
भूत वालाsdjfhfdkßsidjdjhdjfhgjbfdkksksksjsddmdlkttypyp |
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Answer» what is this ?????????? |
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| 27. |
please don't spamno irrelevant stuffno guess class 12 question |
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Answer» your answer is OPTION 3 1.1x10^(-11) |
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| 28. |
किसी आवत में बाई और दाहिनी और बढ़ने पर संयोजकता पहले बढ़ती पुनः घटती है क्यों |
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Answer» Answer: Explanation: ...........KH firm |
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| 29. |
A) Write the electronic configuration ofFe 3+, Cr 3+ , Mn2+ , Zn2+ (At No. of Fe-26 , Cr-24, Mn- 25, Zn- 30 ) |
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Answer» Answer:all answers are MENTIONED below. Explanation: Cr3+ [Ar] 3d4 Mn2+ [Ar] 3d5 Zn2+ [A] 3D10 |
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| 30. |
Determine the volume of 12 gm hydrogen at 1.5 atmospheric pressure at 273°C |
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Answer» gjdgjsltsjlltsjltsustiltsuttjstisltilstsilstilysil |
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| 31. |
Chlorination of ethane in the presence of U. V. light followed by treatment with aq. NaOH gives_______ì |
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Answer» Answer: Think it's Benzoic acid. Explanation: Hope it will HELP you out please follow me and MARK my answer as brainliest answer |
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| 32. |
Match the atomic numbers 4, 14, 8, 15 and 19 with each of the following; (04)a. A solid non- metal of valency 3.b. A gas of valency 2.c. A metal of valency 1.d. A non- metal of valency 4 |
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Answer» Answer: MATCH the ATOMIC numbers 4, 14, 8, 15 and 19 with each of the following; (04) a. A solid non- metal of valency 3. b. A gas of valency 2. c. A metal of valency 1. d. A non- metal of valency 4 |
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| 33. |
Write the examples of odd electron molecule and expanded Octet molecule. |
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Answer» The bonding rules for molecules are GENERALLY applicable, but ... OCTET , (2) odd-electron molecules, and (3) an EXPANDED octet. ... An example is nitrogen dioxide (NO2). |
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| 34. |
The first ionization enthalpy value ( iH) of second period elements Li, Be andC are 520, 899 and 1086 KJ/mol. Predict whether the first iH value will be close to 690 or 990 KJ/mol. Justify your answer. |
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Answer» i will gicv N IPHONW E111 -POR MAX AND GHJIVE 3109000 ,EW,IILLION XB0X TYo7u will WIN a ipojjgoh nw s7121 jd[po9rpj m aytb Explanation: |
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| 35. |
All the elements in a periodic table possess same number of __ in their atom |
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| 36. |
Please answer and fiza online aa jaao please don't spam it is a request |
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Answer» Who are U and fiza APKE DOST hai kay Explanation: |
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| 37. |
The radio isotopes of Cl ( A = 37, Z = 17) and Cl (A= 35, Z= 17) in naturalchlorine is 1:3. Calculate the fractional atomic mass of chlorine |
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Answer» Answer: I don't have any questions PLEASE CONTACT US immediately.... |
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| 38. |
Determine the volume of 12 GM of hydrogen at 1.5 atmospheric pressure at 273°C |
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Answer» Answer: I don't KNOW CHEMISTRY that much but I can tell some ANSWERS |
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| 39. |
Name of the drug contraindicated with digoxin |
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Answer» LSD Explanation: MARK me as BRAINLIEST. |
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| 40. |
Which of THE following used for making road surface |
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Answer» Answer: Composite materials are combinations of both asphalt and CONCRETE, and are typically employed in one of two methods. Asphalt overlays LITERALLY are PLACED over a damaged surface, or alternatively PAVEMENT MAY be cracked and seated instead, forming a true new surface. |
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| 41. |
How many grams of h2o are needed to react with 28.0 grams no2? |
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| 42. |
Carbon lies onin which period in modern periodic table |
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Answer» Answer: It belongs to group 14 of the periodic table. Explanation: Carbon (from Latin: carbo "coal") is a CHEMICAL element with the symbol C and atomic NUMBER 6. It is NONMETALLIC and tetravalent—making four electrons available to form covalent chemical BONDS. It belongs to group 14 of the periodic table. Hope this helps youMark me as a brainliest |
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| 43. |
Which of the following are addition reaction |
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Answer» Answer:(a) and (b) are ADDITION REACTION EXPLANATION: addition reaction is given by PI - electrons. |
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| 44. |
10. A reaction has an enthalpy change of +14 kJ mol^-1 and anentropy change of —37 J K-mol^-1 At whattemperature does this endothermic reaction become spontaneous? |
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Answer» Answer: TH n[0 m,k FOT erthe watthoinc G f9or 9my viude0s and suand subscriibe me iaa asss IB the brwaiinledsts Explanation: |
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| 45. |
How low ionisation energy favours the formation of ionic bond |
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Answer» Answer: In forming an ionic bond, ONE atom must form a cation by LOSING one or more electrons. In general, ELEMENTS having low ionisation ENERGIES have a more FAVOURABLE chance to form a cation, thereby having a greater tendency to form ionic bonds. |
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| 46. |
Draw the line of spectrum of hydrogen atom hen anelectron drop from n=5 to ground estate |
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Answer» No. of LINES =∑(n 2
−n 1
) =∑(6−2) =∑4 =∑ Balmer 4
, Paschen 3
, Brackett2 , Lyman1=10 No. of spectral lines in Balmer SERIES will be in visible range. Hence no. of spectral lines in visible range will be 4. |
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| 47. |
Is cuso4 a trivalent metal??? |
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Answer» Hey mate Explanation: |
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| 48. |
খাদ্য লবণ ও বালুর মিশ্রণে কোন পদ্ধতি ব্যবহার করা হয় |
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Answer» ছাকন ও পরিস্রাবন এবং বাষ্পিভবন Explanation: এটাই CORRECT Answer. পরীক্ষনে উল্লেখ আছে। |
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| 49. |
If the volume of a gas at 300K and 5.1625×10^4 Nm-2 is 1dm3.what will be its volume at STP |
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| 50. |
(ii) BF4^_নিউক্লিওফাইল হিসেবে আচরণ করবে কি না যুক্তিসহ লেখাে। |
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Answer» Answer: I'm not UNDERSTAND your language |
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