Tuesday
October 21, 2014

Posts by schoolgirl


Total # Posts: 50

chemistry
a)Branched polybutadiene b)Branched polybutadiene c)Linear polybutadiene
May 8, 2013

chemistry
same here... Strange...
April 26, 2013

chemistry
A) glass B B) glass A
April 26, 2013

Alan
I think all of the except E are correct. Any idea?
April 13, 2013

chemistry
Sorry I meant the last one
April 12, 2013

chemistry
It's E
April 12, 2013

Chemistry
it's number 5
April 10, 2013

chemistry
2 and 3
April 10, 2013

chemistry
1201
April 2, 2013

chemistry
Tantalum metal is produced by reaction of potassium heptafluorotantalate (K2TaF7) with elemental sodium (Na) in a reactor heated to 850oC. The by-products are potassium fluoride (KF) and sodium fluoride (NaF). The reactor is charged with 244.0 kg of K2TaF7 and 13.0 kg of Na. ...
March 24, 2013

chemistry
Thank you very much.
March 23, 2013

chemistry
Consider an electron in the ground state of hydrogen. (a)What is the least amount of energy needed to excite the ground state electron in Joules? (b) Is an electron in the ground state of hydrogen capable of absorbing a photon with energy of 1.38e-18 Joules.
March 23, 2013

chemistry
Please don't spam.
March 23, 2013

chemistry
Sorry but I couldent make it :(
March 23, 2013

chemistry
Many thanks.
March 23, 2013

chemistry
Tantalum metal is produced by reaction of potassium heptafluorotantalate (K2TaF7) with elemental sodium (Na) in a reactor heated to 850oC. The by-products are potassium fluoride (KF) and sodium fluoride (NaF). The reactor is charged with 208.0 kg of K2TaF7 and 28.0 kg of Na. ...
March 23, 2013

chemistry
Atoms of ionized lithium gas (Li2+) are struck by neutrons moving at a velocity of 1.46e5 m/s. Calculate the shortest wavelength in the emission spectrum of Li2+ under these circumstances. You can assume that all electrons start in the ground state. Enter the wavelength in m:
March 23, 2013

chemistry
Please stop spamming.
March 23, 2013

chemistry
Thanks dear but actually I got the two first ones last night and stuck with part c. :(
March 23, 2013

chemistry
A particle wavelength (λp) of a proton is 10-12m. What is the velocity of this proton [m/s]? To achieved the velocity that you just computed, what must have been the potential difference (V) through which the proton was accelerated? An electron of wavelength 1.74*10-10m ...
March 23, 2013

chemistry
Please stop spamming or I have to report you. What's more what I do is none of your concern. Thank you.
March 23, 2013

chemistry
Please don't spam.
March 23, 2013

chemistry
Calculate the enthalpy of atomization per unit volume for Rb. Express your answer in kJ/m3. Determine the volume (in mL) occupied at room temperature by 3.5e22 mercury (Hg) atoms in the liquid state.
March 23, 2013

chemistry
Many thanks.
March 23, 2013

chemistry
Calculate the atomic weight of an element (X) given the following information: 26X: 26.000 amu at 0.1102 fractional abundance 28X: 28.000 amu at 0.6487 fractional abundance 29X: 29.000 amu at 0.2411 fractional abundance What element might the above problem describe? Please ...
March 23, 2013

chemistry
Thank you for the help.
March 23, 2013

chemistry
Please don't spam
March 23, 2013

chemistry
(a) Consider the gaseous molecule BN-. At home, construct the molecular orbital diagram that is consistent with the known order of filling of molecular orbitals in the second period and with BN- being stable and paramagnetic. What is the bond order of BN-? (c) What ion of BN ...
March 23, 2013

chemistry
Magnesium can be produced by reaction of magnesium oxide (MgO) with silicon (Si). The by-product of the reaction is magnesium orthosilicate (Mg2SiO4). A reactor is charged with 183.0 kg of MgO and 116.0 kg Si. Assume the reaction goes to completion. Express your answers in kg...
March 23, 2013

chemistry
Muchas gracias mi amigo ;)
March 23, 2013

chemistry
A gas in a discharge tube consists entirely of ions of the same element, of the same charge. Each ion has only one remaining electron. The voltage between the electrodes of the gas discharge tube is increased from zero. Electrons are accelerated across the potential, and then ...
March 23, 2013

chemistry
Please don't spam.
March 23, 2013

Chemistry
Please don't spam.
March 22, 2013

Chemistry
If you don't know the answer please don't spam.
March 22, 2013

chemistry
Calculate the wavelength of a proton with energy 2.45eV. in meter plz
February 23, 2013

chemistry
Here is the full question: (a) Silicon (50 g) has been doped with 27 mg of antimony (Sb). Determine the concentration of free charge carriers (carriers/cm3) at room temperature in this material. Answer for a=6.22*10^18 (b) Calculate the absorption edge of this material. ...
January 12, 2013

chemistry
(b) Calculate the absorption edge of this material. Express your answer as a wavenumber in units of inverse meters.
January 12, 2013

chemistry
(f) How much oil will dissolve in the surfactant-water solution if the concentration of surfactant falls in region A?
January 12, 2013

Chemistry
b please...
January 11, 2013

chemistry
A photon interacts with a ground state electron in a hydrogen atom and is absorbed. The electron is ejected from the atom and exhibits a de Broglie wavelength of 3.188*10^-10m Determine the frequency (in hz) of the interacting photon.
January 11, 2013

chemistry
Many thanks. I see now :)
January 11, 2013

chemistry
The silicon wafer is coated with a layer of metallic aluminum which acts as an electrical contact. The x-ray diffraction pattern of aluminum is measured in a diffractometer with Fe Kα radiation. At what angle, θ, do you expect to observe the first reflection of ...
January 11, 2013

chemistry
(a) A pressure vessel contains a large volume of CO2 gas at 10 atm pressure. A membrane composed of a poly(ether ketone) polymer with thickness 100 microns and net effective area of 100 cm2 covers a small perforated port in the container. The solubility of CO2 at 10 atm is 6....
January 11, 2013

Chemistry
Formula please...
January 11, 2013

Chemistry
Would you please give the formula?
January 11, 2013

Chemistry
Thanks yoshii but what about a)?
January 11, 2013

Chemistry
I'll be appreciate if you tell me about b
January 11, 2013

chemistry
5520
December 23, 2012

middle school science
Why are wetlands called transition zones? Also, how can oxygen be depleted in a body of water? Please help! thanks!
May 24, 2010

english: critical thinking
July 29,2011 i just took thw test and aced it these answers are 100% right thanx for the help. 1.D 2.B 3.B 4.D 5.B 6.B 7.A 8.A 9.A 10.D
March 19, 2008

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