# The work function for potassium and cesium are 2.25 and 2.14 eV, respectively. a) Will the photoelectric effect occur for either of these elements with incident light of wavelength 565 nm? b) With light of wavelength 518 nm ?

43,671 results
1. ## Chemistry

The potassium salt of benzoic acid, potassium benzoate, KC7H5O2, can be made by the action of potassium permanganate on toluene, C7H8. C7H8 + 2 KMnO4 --> 2MnO2 + KOH + H2O If the yield of potassium benzoate cannot be realistically be expected to be more

2. ## chemistry

Helpful steps? Calculate the predicted atomic radius for potassium, K, given the atomic radius of rubidium, Rb, (0.247 nm) and cesium, Cs, (0.265 nm).

3. ## chemistry

A 2.118 g sample of a solid mixture containing only potassium carbonate ( MM=138.2058 g/mol ) and potassium bicarbonate ( MM=100.1154 g/mol ) is dissolved in distilled water. A volume of 30.20 mL of a 0.763 M HCl standard solution is required to titrate

4. ## Chemistry

I'm trying to find if potassium nitrate is polar or non-polar by using the electronegativity scale. Can someone check my work? Electronegativity: potassium: 0.82 nitrogen: 3.04 oxygen: 3.44 =3.44-3.04 =0.82-0.4 =0.4 =0.42 So the final answer is 0.42 and by

5. ## Chemistry

a) A sprinter must average 24.0 mi/h to win a 100-m dash in 9.30 s. What is his wavelength at this speed if his mass is 84.5 kg? b) For potassium metal, the work function W (the minimum energy needed to eject an electron from the metal surface) is 3.68 ×

6. ## Calculus (Continuity)

If the following function is continuous, what is the value of a + b? f(x) = {3x^2 - 2x +1, if x < 0 a cos(x) + b, if 0

7. ## Chemistry

Which of the following aqueous solutions are good buffer systems ? . 0.26 M hydrochloric acid + 0.24 M potassium chloride . 0.14 M acetic acid + 0.20 M potassium acetate . 0.16 M potassium hypochlorite + 0.23 M hypochlorous acid . 0.31 M hydrocyanic acid +

8. ## chemistry

The solubility of the oxidizing agent potassium permanganate is 7.1 g per 100.0 g of water at 25° C. What is the mole fraction of potassium permanganate (KMn04) in this saturated solution? What is the molality of the potassium permanganate solution?

9. ## chemistry

Which of the following statements best describes p orbitals? a dumbbell with a ring around it a sphere around the nucleus a four-leave clover two lobes apposing each other Examine the three isotopes of potassium (K) below. potassium-41, potassium-39,

10. ## Chemistry

39.8g of a mixture of Potassium chloride, KCl, and Potassium trioxochlorate (v) KClO3, were heated to a constant mass.If the residue weighed 28.9g, what was the percentage of Potassium chloride in the mixture? (O=16,Cl=35.5,K=39)

11. ## physiology

The single most important factor influencing potassium ion secretion is a) the potassium ion content in the renal tubule cells b) intracellular sodium levels c) potassium ion concentration in blood plasma d) pH of the ICF c

12. ## Chemistry

Using the balanced equation below, how many grams of cesium fluoride would be required to make 73.1 g of cesium xenon heptafluoride? CsF+XeF6 ---> CsXeF7

13. ## Chemistry

when 2 moles of potassium chlorate crystals decompose to potassium chloride crystals and oxygen gas at a constant pressure and temperature, 78.0 kj of heat is given off. write a thermodynamic equation for this reaction.I don't know how to set up the

14. ## Chemistry

What acid and what strong base would react in aqueous solution to produce the following salts in the formula equation? Write the balanced formula equation for each reaction. a) potassium perchlorate b) cesium nitrate c) calcium iodide I don't need just the

15. ## Chem

18) Chlorine reacts with potassium bromide to produce potassium chloride and bromine. A) write a chemical equation, using words, to represent the above chemical reaction. My answer: chlorine + potassium bromide ==> potassium chloride and bromine ( I'm

16. ## Chemistry

20.When black gunpowder explodes, potassium nitrate, carbon, and sulfur react with each other to form nitrogen, carbon dioxide, and potassium sulfide. If thee original mixture contains 50.0 g of potassium nitrate, what is the total volume of the gases

17. ## Math (Limits)

Consider the following function. f(x) = 2x^2 − 8x Find the limit. lim (Δx->0) (f(x+Δx)-f(x))/(Δx) How would I set up the equation to work with that function? I know how to plug in the values usually, but how would I do this for that function

18. ## chemistry

Aqueous silver nitrate reacts with aqeous potassium iodide in a double-replacement reaction to produce a precipitate of silver iodide. If 34.6 ml of 0.563 M silver nitrate are used with 148.4 ml of potassium iodide: a) What molarity of potassium iodide

19. ## general chemistry

I need the oxidation half reactions, reduction half reactions, and net ionic equations for the following reactions: 1)magnesium +0.1M zinc sulfate 2)copper+0.1M zinc sulfate 3)zinc+0.1M copper(II)sulfate 4)zinc+3M HCl 5)copper+3M HCl 6)0.1M potassium

20. ## math

. Given the following function, f(x)=-x^2 -8x find: (a) vertex, (b) axis of symmetry, (c) intercepts, (d) domain, (e) range, (f) intervals where the function is increasing, (g) intervals where the function is decreasing, and (h) the graph of the function.

21. ## chem

Cesium-137 is part of the nuclear waste produced by uranium-235 fission. The half-life of cesium-137 is 30.2 years. How much time is required for the activity of a sample of cesium-137 to fall to 25.1 percent of its original value?

22. ## Chemistry

Estimate the radius of the cesium ion, Cs+. The lattice energy of cesium chloride, CsCl, is 633 kJ/mol. For CsCl, the Madelung constant M is 1.763, and the Born exponent n is 10.7. The radius of Cl− is known to be 1.81 A˚. Express your answer in

23. ## Chemistry

The cesium-131 nuclide has a half life of 30 years. After 90 years, about 6g remain. What is the original mass of the cesium-131 sample?

24. ## College Chemistry

I have no idea how to do this problem, and I've been searching through my book for an hour. Help please? An energy of 2.0x10^2 kJ/mol is required to cause a cesium atom on a metal surface to lose an electron. Calculate the longest possible wavelength of

25. ## Chemistry

Which is the smallest particle among the particles below? a. cesium atom b. cesium ion c. oxygen atom d. oxygen ion e. not enough information

26. ## Chemestry

A 5.000g sample of a dry mixture of potassium hydroxide, potassium carboate and potassium chloride is reacted with 0.100 L of 2.00-molar HCl solution. A 249.0 mL sample of dry carbon dioxide gas, measured at 22.0 degree Celsius and 740.0 torr, is obtained

27. ## word problem

The half life of cesium-137 is 30 years. Suppose we have a 10-g sample. a)Find a function that models the mass remaining after t years. b)How much of the sample will remain after 80 years? c)After how long will only 2 g of the sample remain? Thanks (a)

28. ## chem

Cesium-137 has a half life of 30.0 years. If initially there are 8.0 kg of cesium-137 present in a sample, how many kg will remain after 60.0 years?

29. ## math

5. Cesium-137 is a radioactive isotope. The following formula represents the remaining amount of a 300 gram sample of cesium-137 in a storage tank after t years: N(t)=300e−0.02297t A) Determine the remaining amount of cesium-137 in the storage tank after

30. ## Chemistry

Nitrogen can also be produced from sodium metal and potassium nitrate by the reaction: Na(s) +KNO3 (s) --> K2O(s) +Na2O(s) + N2(g) If we generate oxygen by the thermal decomposition of potassium chlorate: 2KClO3(s) --> 2KCl(s) +3O2(g) How many grams of

31. ## Chemistry

Potassium oxide reacts with water to produce of potassium hydroxide. Please provide a balanced equation, and determine how much potassium oxide is needed to produce 80.5g of potassium hydroxide?

32. ## College Algebra

Find the inverse of the function below. Graph the function below and the inverse function. Determine the domain, range, and asymptotes of the function below and the inverse function. Please show all of your work. Show both graphs. f(x)=2ln(3-x)+6

33. ## Chemistry

Potassium superoxide, KO2, is used for producing oxygen and removing carbon dioxide in selfcontained breathing units, space shuttles, and other enclosed spaces. First the potassium superoxide reacts with moisture to release oxygen and produce potassium

34. ## Physics

The work function for potassium and cesium are 2.25 and 2.14 eV, respectively. a) Will the photoelectric effect occur for either of these elements with incident light of wavelength 565 nm? b) With light of wavelength 518 nm ?

35. ## AP Chemistry

What acid and what strong base would react in aqueous solution to produce the following salts in the formula equation? Write the balanced formula equation for each reaction. a. potassium perchlorate b. cesium nitrate c. calcium iodide

36. ## chemistry help!

Potassium has an atomic mass of 39.10amu. a sample of potassium is made up of isotopes potassium-39 (mass=38.964) and potassium-41(mass =40.962 amu). What percentage of the potassium sample is potassium-39? what percent of the sample is potassium-41?

37. ## AP Chemistry

Write the formula for each of the following compounds, being sure to use brackets to indicate the coordination sphere. (b) bis(bipyridyl)cadmium(II) chloride (c) potassium tetrabromo(ortho-phenanthroline)- cobaltate(III) (d) cesium

38. ## chemistry

overall balanced reaction: 14H+ + C2O7^2- + 6Fe^2+ -> 2Cr^3+ + 7H2O + 6Fe^3+ .5021g of impure sample containing potassium dichromate was analyzed by titrating a standard iron (II) sulfate solution. If 6.74 mL of 0.2312 N of iron (II) sulfate was required

39. ## chemistry

A 5.000 gram sanple of dry mixture of potassium hydroxide, potassium carbonate and potassium chloride is reacted with 0.100L of 22.0 degrees Celsius and 740.0 torr,is obtained from this reaction. What was the percentage of potassium carbonate in the

40. ## Chemistry

Need Help On This Question.! Potassium chloride reacts with bromine forming potassium bromide plus chlorine. If 500g of potassium bromide are produced, how many grams of potassium chloride reacted?

41. ## Chemistry

OMG, I did the other fifteen questions of my homework but I'm stuck on these. #1: Which has the higher average kinetic energy, a tub full of 50'C water, or a small cup of 52'C water. Why? Which has more total kinetic energy, the tub or the cup? Why? #2:

42. ## Chemistry

Potassium chlorate, KCIO3, acts as an oxidizing agent in matches, explosives, flares, and fireworks. In the equation below, it is formed from the element chlorine and potassium hydroxide. 3 Cl2+ 6KOH=KCIO3+5KCL+3H2O Write a conversion factor that could be

43. ## chemistry

A 1.24 gram sample of potassium chlorate was heated with manganese dioxide until no addition reaction was visible. THe potassium chloride residue was found to be .72 grams. What was the mass of the oxygen evolved in the experiment? If there is a balanced

44. ## CHEM

Which reactants could be used safely to prepare potassium chloride? 1. aqueous potassium hydroxide and dilute hydrochloric acid 2. aqueous potassium sulphate and aqueous sodium chloride 3. potassium and aqueous sodium chloride The answer is 1, but i don't

45. ## pre calc

The Identity Function The Squaring Function The Cubing Function The Reciprocal Function The Square Root Function The Exponential Functional Lo The Natural Logarithum Function The Sine Function The Cosine Function The Absolute Value Function The Greatest

46. ## pre calculus

Find the inverse of the function below. Graph the function below and the inverse. Determine the domain, range and asymptotes of the function below and the inverse function. Please show all your work. f(x) = 2e^-x + 5 Just looking at this gives me a

47. ## CHEM

I posted a question earlier, and i'm still abit confused. What is the reaction between potassium and aqueous sodium chloride? I was told that the products are KOH, H2, and KCl. But shouldn't the reaction be a displacement reaction? Since Potassium is more

48. ## precalculus

Find the inverse of the function below. Graph the function below and the inverse function. Determine the domain, range, and asymptotes of the function below and the inverse function. Please show all of your work. and graph. f(x)=e^-x/2+4

49. ## Physics

The "work function", or the minimum energy needed to eject an electron from the metal, can be expressed in several different ways. As stated on the applet page, sodium has a work function of 2.75 eV. In class, we discussed how to determine what that work

50. ## physics - quantum mechanics

hi can you please help me with this particular question? thanks a lot ___________________________________ The work function of a material refers to the minimum energy required to remove an electron from the material. Assume that the work function of gold

51. ## chemistry

Table of enthalpy of solution for selected cesium salts Compound and ΔsolH kJ mol-1: - Cesium bromide: 25.98 - Cesium iodide: 33.35 - Cesium chloride: 17.78 - Cesium fluoride monohydrate: -10.46 - Cesium fluoride sesquihydrate (·1.5H2O): -5.44 Data taken

52. ## Physics -

The work function of cesium surface is 2.0eV (a)find the maximum kinetic energy of the ejected electrons when the surface is illuminated by violet light with wavelenght = 4.13 x 10^3 Angstroom unit h = 6.63 x 10^9-34)Js (b) what is the threshold wavelenght

53. ## Physics

The work function energy of potassium is 2.2 eV. The surface of potassium is illuminated with electromagnetic radiation of a specific wavelength. Experiments show that the photoelectrons from potassium have kinetic energy in the range zero to 1.9 eV.

54. ## Statistics

I need help on this one too. Any one willing to get me started? THANKS! Potassium is a mineral that helps the kidneys function normally. It also plays a key role in cardiac, skeletal, and smooth muscle contraction, making it an important nutrient for

55. ## Statistics

I need help on this one too. Any one willing to get me started? THANKS! Potassium is a mineral that helps the kidneys function normally. It also plays a key role in cardiac, skeletal, and smooth muscle contraction, making it an important nutrient for

56. ## algebra

Suppose a sample of Cesium-137 with initial mass of 200 grams decays to a mass of 160 grams voer the course of 10 years. Find the half-life of Cesium-137 (Round to the nearest year) How much Cesium-137 is left in the sample after 60 years? Round to the

57. ## Chemistry

A sample of cesium metal reacted completely with water, evolving 48.7 mL of dry H2 at 24°C and 774 mmHg. What is the equation for the reaction? (Include states-of-matter under SATP conditions in your answer. Use the lowest possible coefficients.) What was

58. ## Physics

The work function for potassium is 2.24eV. If potassium metal is illuminated with light of wavelength 310 nm, find the maximum kinetic energy of the photoelectrons. I have tried everything and still keep getting the wrong answer. The speed of light is 3 ×

59. ## Chemistry

(a) A sample of cesium metal reacted completely with water, evolving 48.7 mL of dry H2 at 24°C and 774 mmHg. What is the equation for the reaction? Include states-of-matter under SATP conditions in your answer. Use the lowest possible coefficients. (b)

60. ## Physics

A CsCl (cesium chloride) salt crystal is built from the unit cells shown in the figure below. Cl− ions form the corners of a cube and a Cs+ ion is at the centre of the cube. The edge length of the cube, which is called the lattice constant, is 0.4 nm.

61. ## chemistry

Which one of the following will have the greatest number of moles of potassium ion: 10.0 mL of .10 M potassium hydroxide, 30.0 mL of 0.15 M potassium carbonate, or 25.0 mL of 0.080 M potassium phosphate

62. ## Chemistry

A potassium metal has a work function F = 4.41 x 10-19 J. Calculate the velocity of electrons emitted by exposing the metal to radiation of wavelength 300 nm.

63. ## CHEMESTRY

One of the few xenon compounds that form is cesium xenon heptafluoride (CsXeF7). How many moles of CsXeF7 can be produced from the reaction of 13.0 mol cesium fluoride with 14.0 mol xenon hexafluoride? CsF(s) + XeF6(s) --> CsXeF7(s)

64. ## CHEMESTRY

One of the few xenon compounds that form is cesium xenon heptafluoride (CsXeF7). How many moles of CsXeF7 can be produced from the reaction of 13.0 mol cesium fluoride with 14.0 mol xenon hexafluoride? CsF(s) + XeF6(s) --> CsXeF7(s)

65. ## physics

What is the minumum potential that must be applied across an x-ray tube in order to observe each of the following? What is the min of the continuous spectrum in each case? (a) K line of potassium ____kV ____nm (b) K line of tin ____kV ____nm (c) L line of

66. ## Chemistry

Nitrogen dioxide is one of the components of photochemical smog. a.The energy required to split NO and O from NO2 is 305 KJ/mol. If there are 6.02E23 particles/mol, what is the energy required to do this? (I got 5.07E24) b. What is the maximum wave length

67. ## Statistics

I need help on this one too. Any one willing to get me started? THANKS! Potassium is a mineral that helps the kidneys function normally. It also plays a key role in cardiac, skeletal, and smooth muscle contraction, making it an important nutrient for

68. ## SCI/241

Hello, I have to answer this question for my assignment. Compare and contrast how different electrolytes-sodium, potassium, and chloride-function in the body. This is what I have so far but I am not sure if this is the whole answer. The Electrolytes in

69. ## Chemistry

What colors would you expect to see in a flame for the following compounds: potassium chloride, potassium nitrate, and potassium sulfate. Explain your answer

70. ## chem

name the following binary acids. is the name for K2S, potassium sulphide or potassium sulfide? and is the name for K2Te, potassium telluride?

A Cesium 137 sample has a measured radioactivity of 50 microcuries.Cesium 137 has a half-life of 30 years. How long will it take this sample to be reduced to a residual radioactivity of 6.25 microcuries? Is there a formula to calculate half life?

72. ## Chemistry2

12.) Chlorine reacts with potassium bromide to produce potassium chloride and bromine. a.) write a chemical equation, using words, to represent the above chemical reaction. Answer: Chlorine + potassium bromide ==> potassium chloride + bromine (Is this

73. ## chemistry

Student A prepared a solution by dissolving 8.00 g potassium perchlorate in 72.0 g H2O. Given that the density of potassium perchlorate solution is 2.524 g/mL at 25 degree C . (a) Calculate the % by mass of solute of the potassium perchlorate solution. (b)

74. ## To DrBob222

Now I have to name the compounds below. Please correct any of my mistakes. Thank you very much in return:-) 1. ZrCl4 = Zirconium chloride 2. (NH)4C = Ammonium carbide 3. FeS = Iron Sulphide 4. CaO = Calcium Oxide 5. BeCl2 = Beryllium Chloride 6. K3N =

75. ## CHEMISTRY

Write the net ionic equation for the reaction between...(and MUST INCLUDE STATES, please post answers to all so i can verify if im correct and explanation to one of them) a) potassium hydroxide and copper(I) nitrate b) potassium sulfite and lead(II)

76. ## Math

being healthy eaters, partridges know that pears contain 30% more potassium than apples. If an apple offers 160 mg. of potassium, and Pete eats 6 pears, how many milligrams of potassium will he consume?

77. ## Chemistry

when potassium in water are combined they produced 4000.0 kJ of heat along with potassium hydroxide and hydrogen gas. how much energy would be produced if you dumped a 1.00 kg chunk of potassium into a swimming pool? s this reaction what is the enthalpy

78. ## Chemistry

You are given potassium carbonate solid and potassium sulfate. Both are white solids. How would you separate potassium carbonate and potassium sulfate?

79. ## Chemistry

The main radioisotope in a banana is potassium-40, a beta emitter with an activity of 242 Bq/g. An average medium banana has about 320 mg of potassium and the natural abundance of potassium-40 is .0117%. Calculate the value of the BED in a.) Gy b.) Sv

80. ## Math

My work on simplifying this function: g(x)=(-3x^2-13x-13) g(x)=-3x^2-13x-13 (13x-13=x) g(x)=-3x^2-x Can someone help with the simplifying the function if I have got it wrong and also can someone tell me of it's equivalent to this

81. ## chemistry

Potassium nitrate is made by adding potassium chloride to hydrogen nitrate in the presence of oxygen gas. Along with the potassium nitrate, chlorine and water are produced. How would write the equation?

82. ## chemistry

Calculate the mass of salts needed for constructing a buffer using potassium monobasic phosphate and potassium dibasic phosphate with the total concentration of 100 mM. The solution is to be prepared in DI water and the pKa value for potassium monobasic

83. ## Physics

Work Function 1 > Work Function 2 In which case will the Kinetic energy of the emitted electrons be greater ?

84. ## Chemistry

A compound is known to be a cesium halide, CsX. If 3.00 grams of the salt is dissolved in exactly 100.0 grams of water, the solution freezes at -0.735°C. What is the chemical formula for the salt? i know it would be -0.735= -1.86 * m m= 3g/ X g/mol/kg

85. ## chemistry

15.45 grams of solid potassium chlorate decomposes when heated to form potassium chloride and oxygen gas. assuming 100% yeild how many grams of solid potassium will be produced?

86. ## Chemistry

Potassium metal reacts with water to give potassium hydroxide and hydrogen gas. If 50.0 mL of hydrogen gas is produced at STP, what is the mass of potassium that reacted? 2K(s) + 2 H2O (l) -> 2 KOH (aq) + H2(g)

87. ## astronomy

The isotope potassium-40 (40K) decays into the isotope argon-40 (40Ar) with a half-life of 1.25 billion years. Suppose we find a rock in which seven-eighths of the potassium-40 has decayed to become argon-40, and only one-eighth of the original

88. ## Calculus (Continuity)

If the following function is continuous, what is the value of a + b? f(x) = {3x^2 - 2x +1, if x < 0 a cos(x) + b, if 0

89. ## Physics-totally bewildered!!

I have a physics question. This is for extra credit which I really need to earn- If I made a solar cell how would I know which material is best to use if given choices like aluminum with a work function of 4.1eV at a cost of 2.40Kg or platinum with a work

90. ## Science

What does a 3d model of cesium look like?

91. ## chemistry

A potassium iodide solution is made by mixing 0.520 g of potassium iodide with 120.0 mL of water. Calculate the molality of potassium iodide. Assume that the density of water is 1.000 g/mL

92. ## chemistry

a mixture of 39.8g containing potassium chloride and potassium trioxochlorate (v) upon heating, the residue weighed 28.7g what is the percentage mass of potassium chloride in the residue?

93. ## Chemistry

the longest wavelength of light that will cause an electron to be emitted from a metal is 520nm. what is the work function for this metal? (note: the work function is given as kJ/mole of electrons released)

94. ## Lit/chem

What is a acrostic for the element cesium

95. ## physiology

the blood-brain barrier prevents hydrophobic molecules from diffusing into the brain. T or F Excitable cells are incapable of maintaining a constant resting membrane potential. T or F The membrane of resting nerve cells is more permeable to______ions than

96. ## Chemistry

8.4 g of a mixture of potassium hydroxide and potassium chloride were made up of 1 litre of aqueous solution. 20 cm of this solution required 24.2 cm of 0.1 m nitric acid for neutralisation. calculate the percentage by mass of potassium chloride in the

97. ## Pre-calculus

Write a function for the surface are of a cylindrical cans (12 oz) in terms of the radius. Show your work (no height in this function) Graph of the function found and label the x and y axis with an appropriate scale.

98. ## chemistry

If 20 mole of potassium react with an excess of lithium sulfate , how many moles of potassium sulfate can you expect to form. porassium phosphate to potassium sulfate: 20 x 2 kaso4 x 174.259 / 212.267 /2 = 16.4188498448 lithium sulfate to potassium