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the shortest and longest wavelength series in singly ionized helium is 22.8nm and 30.4nm . Are they right? How many orders we can see between the angles range observations 30 and 90 in the Balmer's series?

15 years ago

Thank you drwls, My problem is a. The lifetime of the levels in a hydrogen atom are of the order 10-E8s. What is the evergy uncertainty of these states? Compare this result with the energy value of the first excited state. b. Find the shortest and the lon...

15 years ago

What is the minimum lens size (in meters) that will permit just resolving 2 stars 1.1 second apart using light of 510nm?

15 years ago

Why do the molecules that have the structures such as H2C=C=CH2 or HO-CH=CH2 are unstable?

15 years ago

6.2(+_ 0.2) - 4.1 (+_ 0.1 ) + ? [6.2( +_ 0.2) - 4.1(+_ 0.1)] : 9.43(+_0.05) find absolut uncertainty and relative uncertainty. PLEASE HELP:I solved them and got the exact absolute uncertainty like the answer key, but I didn't get right answer of relative...

15 years ago

Species of arsenic found in kriking water include (AsO3)3-, (CH3)2(AsO2)2-, (CH3)AsO3 2-, and (AsO4)3-. Pure water containing no arsenic was spiked with 0.40microgram arsenate/L. Seven replicate determinations gave 0.39, 0.40, 0.38, 0.41, 0.36, 0.35 and 0...

15 years ago

how many milliter of .246 M HNO3 should be added to 213 ml of 0.00666 M 2,2'-bipyridine to give a pH of 4.19? please help, does this problem need to be solved with ka or kb?. Is 2,2'- bipyridine a base, this is the problem from my text book, but it is not...

15 years ago

What is the chemical formula of fertilizer 13-13-13. Pleas tell me. Thanks a lot

15 years ago

Br is larger than Cl,yet the two atoms have identical axial destabilization energies. Why?

15 years ago

1.calculate the commutators a/ [x^2,p^2] b/ [a,a^+n] I don't know how to solve it. Please help. I really appreciate.

15 years ago

why we have to normalize the proton NMR areas to determine the mole % oa a compound in a mixture?

15 years ago

Ionic bonds and covalent bonds, which one is the stronger. My present teacher said that covalent bond is the strongest one. I learned ionic interaction is the strongest and many chem. books say so. Now i am confused. Is my present teacher right. Please ex...

15 years ago

Please tell me where I can find the articles ( free) to represent the Setvens rearrangement and Favorskii rearrangement. I have to have them for presentation but I have not taughed about these reaarangenment yet. I hope somebody on Jiskha will help me to...

14 years ago

start from the Maxwell-Boltzmann distribution and derive an expression for the most probable speed of a gas of molecules at a temperature T. Go on t demonstrate the validity of the equipartition conclusion that the average translational kinetic energy of...

14 years ago

please help me to solve it, thank you so much in advance: propose organic compounds that are isolable with 1. Mn(CO)5(CpCo)(CpCo)C(Co(CO)4)3 2. Cr(CO)4(ì-PH)Cp*Mn(CO)

14 years ago

the aprroximate method to solve the shrodringer equation for hydrogen like atom? Please help, thank

14 years ago

I am trying to calculate geometry optimization of cyclodextrin, however, the computer always show error 2070 in gaussian. I used sem-empirical pm3 and try pm6, and tried to find any method to do this work, but every try could not work. I hope any body on...

13 years ago

South Africa gained its independence from Britain in 1910. Why did this not lead to freedom and equality in South Africa What was that policy called!?

3 years ago

x^2 - 3x -20

3 years ago

In which sentence is the underlined word the SIMPLE PREDICATE? A. According to legend, there is buried pirate treasure nearby. B. People with metal detectors search for it every weekend. C. So far, no treasure has been found. D. Most treasure seekers leav...

3 years ago

Is D~11.7*10^-2

15 years ago

i solved D~11.7*10^-2, but the answer key is .0956

15 years ago

increasing atomic radius: oxygen<carbon<aluminum<potasium

15 years ago

neon<oxygen<sulfur<aluminum

15 years ago

ionization energy is the minimum energy (Kj/mol)required to remove an wlectron from a gaseous atom in its ground state. affinity energy: the negative of the energy change that occurs when an electron is accepted by an atom in the gaseous state to form an...

15 years ago

Electronegativity of fluorine is the highest among the chemical element(its electronegativity = 4),so F tends to receive electron, not yield. Therefore, fluorine has the higher ionization energy than iodine.

15 years ago

the properties of elements are based on the valence electron, the elements in the same family generally have similar properties because they have the same number of valence electron.

15 years ago

They are correct b) (1.2,0) and(0,20

15 years ago

deltaG = -RTlnK R=8.314J/mol.K you got R, T so K found by that formula.

15 years ago

let y=0, --> x= 6/5=1.2 let x=0 --> y = 6/3 = 2

15 years ago

as t-->0, we have 8t-->0, so lim (sin(8t))^2/t^2 = [lim sin(8t)/t].[limsin(8t)/t] as8t-->0 =8.[limsin(8t)/8t].8[limsin(8t)/8t], 8t-->0 = 8*1*8*1= 64 you know the formula lim (sint/t)=1 as t-->1, aren't you?

15 years ago

y' = (3-secx)'tanx -(3-secx)(tanx)'/(tanx)^2 = -secx(tanx)^2 - (3-secx)secx/(tanx)^2 = -secx[(tanx)^2 + (3-secx)]/tan^2x =-[(tan)^2 +3 -secx]/sinx

15 years ago

4.6*10^-3 = [NO2]^2/[N2O4] => [NO2] =3.48*10^-1

15 years ago

MnO4- +5e -> Mn2+}*2 C+1 -2e -> C+3 }*5 2MnO4- + 5C6H7O +6H+ -> 2Mn2+ + 5C6H7O2 + 3H2O Step 1: realize the oxidation of element: (oxidation of H and O not change) write half reaction equalize the number of election yieled and accepted by the coefficient (...

15 years ago

mol Na2S = (0.01mol/L)*2.00ml*1L/1000mL = 0.002mol mol Hg(NO3)2 = 50.0ml*(0.0005mol/L)*1L/1000mL = 0.000025=2.5*10^-5 Hg(NO3)2 limiting reagent max mass of precipitate = 2.5*10^-5 * molar mass of Hg(NO3)2

15 years ago

babyface is correct :) i got 100

4 years ago