1. **CHEM

    Place the following elements in order of Decreasing atomic size: tellurium, bromine, argon, cesium, strontium, and selenium. would the correct ranking then be: Cs, Sr, Te, Se, Br, Ar ??? or am I still way off??
  2. CHEM**

    I just have 2 other questions that I just want to make sure on: Place the following elements in order of decreasing atomic size: tellurium, bromine, argon, cesium, strontium, and selenium. (Te, Br, Ar, Cs, Sr, Se) ~~(or...the correct ranking cannot be
  3. Atomic Size

    Place the following elements in order of decreasing atomic size: selenium, chlorine, fluorine, rubidium, calcium, and sulfur.
  4. Chemistry

    Place the following elements in order of decreasing atomic size: selenium, chlorine, fluorine, rubidium, calcium, and sulfur.
  5. Chemistry

    Place the following elements in order of decreasing atomic size: selenium, chlorine, fluorine, rubidium, calcium, and sulfur.
  6. I don't understand this chemistry problem?

    The question reads: Place the following elements in order of decreasing atomic size: selenium, chlorine, fluorine, rubidium, calcium, and sulfur. I looked this up on a periodic table and my answer was: Rb, Se, Ca, Cl, F, S. This is still marked wrong, and
  7. Chem - Elements

    I need help on identifying four elements. 1. a member of the same family as oxygen whose most stable ion contains 54 electrons. (Sulfur?) 2. member of alkali metal family whose most stable ion contains 36 electrons. (Cesium??) 3. noble gas with 18 protons
  8. Chemistry

    Sort the following elements by electron affinity, from most positive to most negative EA value: bismuth, chlorine, helium, cesium, and tellurium.
  9. Gps

    Arrange in order of increasing atomic size use appropriate < > -= symbol to separate substances in the list 1. The period 2 elements Be,B and N The group 4A elements Sn,Si, and Pb
  10. Chem

    Rank thefollowing elements in order of decreasing atomic radius. N, B, Be, Li? I thought it was N, B, Be, Li
  11. Chemistry

    Bromine has two naturally occurring isotopes. Bromine-79 has a mass of 78.918 amu (atomic mass unit) and is 50.69% abundant. Using the atomic mass reported on the periodic table, determine the mass of bromine-81, the other isotope of bromine.
  12. Chemistry

    12) Naturally occurring argon is composed of 0.3365% of 36Ar (atomic mass, 35.9675 u), 0.0632% of 38Ar (atomic mass, 37.9627 u), and 99.6003% of 40Ar (atomic mass, 39.9624 u). Use these data to calculate the average atomic mass of argon.
  13. science

    1. When Mendeleyev arranged the elements into the periodic table, he found that elements with fell into groups on the table A. the same mass B. similar size C. Similar properties D. The same color 2. Every element has its own atomic number. The atomic
  14. chemistry

    Examine the elements listed below. nitrogen (N), phosphorus (P), arsenic (As) Which of the answer choices accurately describes a common property of these elements? they have the same amount of atomic mass they have the same amount of reactivity they have
  15. Chemistry

    Bromine has two isotopes, Br- 79 and Br- 81. The relative atomic mass of bromine is 79.9. CALCULATE THE PERCENTAGE of Br-79 atoms in a sample of bromine. PLease help i'm really stuck
  16. Modern Chemistry

    Bromine has two naturally occurring isotopes. Bromine-79 has a mass of 78.918 amu and is 50.69% abundant. Using the atomic mass reported on the periodic table, determine the mass of bromine-81, the other isotope of bromine.
  17. Chemistry

    bromine has two isotopes Br,79 and Br-81 the relative atomic mass of bromine is 79.9 calculate the percentage or br 79 atoms in a sample of bromine show all working out with all equations used and no abbreviations please
  18. chem

    Bromine consists of two major isotopes with the following percent abundances and atomic masses: 79Br (50.54% and 78.918 amu) and 81Br (49.46% and 80.916 amu). Calculate the average atomic mass of bromine.
  19. chemistry

    1) Rank the elements, aluminum, sodium and phosphorus, in order of decreasing conductivity. 2) Rank the elements aluminum, gallium, and boron in order of decreasing conductivity
  20. physics

    Argon is a monatomic gas whose atomic mass is 39.9 u. The temperature of eight grams of argon is raised by 95 K under conditions of constant pressure. Assuming that argon behaves as an ideal gas, how much heat is required?
  21. **CHEM**

    Arrange the following elements in order of decreasing atomic radius: Cs, Sb, S, Pb, Se *(list from largest to smallest...or..."the correct ranking cannot be determined") ***I think the answer 'should be', from largest to smallest: ***Cs, Pb, Sb, Se,
  22. chemistry

    1. A 12.5843g sample of zrbr4 was dissolved and after several steps all of the combined bromine was precipitated as ArBr. The silver content of AgBr was found to be 13.12160g Assume the atomic masses of silver and bromine to be 107.868 and 79.904.what
  23. AP Chemistry

    A 12.5843 g sample of ZrBr4 was dissolved and, after several chemical steps, all of the combined Bromine was precipitated as AgBr. The silver content of the AgBr was found to be 13.2160 g. Assume the atomic weights of silver and bromine to be 107.870 and
  24. chemistry

    Given the following Unknown atoms with their respective atomic numbers, X; Atomic number 19, Y; Atomic number 15, a. Deduce the identities of the elements X and Y. b. What are the mass numbers of the two elements X and Y? c. Calculate the number of
  25. 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
  26. Math

    The element strontium-90 is radioactive. The percent of strontium -90, A(t), left in a sample can be modelled by the half-life function A(t) = A0 (1/2)^t/29, where t represents the time, in years, after the initial time, and A0 represents the initial
  27. Chemistry

    The isotopes of argon have the following relative abundances: Ar-36 0.34% Ar-38 0.06% Ar-40 99.66% Estimate the average atomic mass of argon. How would I go about doing this?
  28. chemistry

    consider the elements;Na,Mg,Cl and F.state with reasons,which element has the highest electronegativity. 2. Arrange with reasons, the elements in decreasing order of ionization energy
  29. Chemistry

    Five grams of sodium are combined with unlimited bromine. How many moles of bromine are used up? How many liters of bromine would be used if the reaction took place at STP? My answer: .1088 mole Br2 and 2.44 L Br2
  30. Chemistry

    Five grams of sodium are combined with unlimited bromine. How many moles of bromine are used up? How many liters of bromine would be used if the reaction took place at STP? My answer: .1088 mole Br2 and 2.44 L Br2
  31. Chemistry

    What is the trend in atomic size in the series of Group IIA elements Be through Ra?
  32. 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).
  33. science chem

    give one example of two elements that would be placed incorrecty if they were in order of their relative atomic masses. and explain why placing these two elements like this would not be correct. Pleasw could someone help me. Co/Ni is one. Ar/K is a second
  34. Chemistry

    Help arrange these elements in decreasing order of metallic property I, Mg, Al, Rb, Ca
  35. Chemistry

    Please help me arrange these elements in decreasing order of metallic property. I, Mg, Al, Rb, Ca Thank You
  36. Chemistry

    Bromine has two isotopes, Br- 79 and Br- 81. The relative atomic mass of bromine is 79.9. CALCULATE THE PERCENTAGE of Br-79 atoms in a sample of bromine. PLease help i'm really stuck Someone said: The total for 79 and 81 is 100% and the total for fraction
  37. Science

    Tellurium is a metalloid. How many valence electrons does tellurium have? 3 4 5 6
  38. Chem

    Order the elements S, Cl, and F in terms of increasing atomic radii. I thought the answer was F, S, Cl, but the answer key said it was S, F, CL Why? AR decreases from left to right. Sulfur has one more energy level, so shouldn't its atomic radii be greater
  39. CHEM

    Arrange the elements in decreasing order of the number of valence electrons Br,S,Sb,Sr,F,Mg,I,Ca,Na,Kr,Xe,Bi,Ge,Ga,K
  40. chem help

    Arrange the following elements in order of increasing atomic radii. Sr, Rb, Sb, I, In
  41. chemistry

    arrange the following elements in order of increasing atomic mass; Cu, C, K, H, F, Cl, Xe, Cr, Pb, Na
  42. chemistry

    which of the following is true regarding the transition elements? A. Multiple oxidation states resulting from the involvement of d electrons in bonding is a characteristic of transition elements. B. Most transition elements have lower melting and boiling
  43. physical science

    Thanks got through all but one Element P has an atomic number of 92 and atomic mass of 238. Element s has 92 protons and 143 neutrons. atomic number and protons are the same would htese two elements be an isotope or different elements
  44. Chemistry

    7. Which of the following is true? A. Cesium is the most active group 1 metal, because its valence electron is held more tightly than the others in the same group. B. Group 1 elements are more reactive than the group 2 elements because they have more
  45. chem

    Radioactive substances decay by first-order kinetics. How many years would be required for a sample containing strontium-90 to decrease to 58.32% of its initial activity? The half-life of strontium-90 is 2.88e1 years.
  46. Nuclear Physics

    A meteorite has landed at UOIT! Chemical analysis shows that it contains 1 gram of potassium and 1E-5 grams of argon, assumed to be present entirely from the decay of K-40. Assuming that no argon has escaped the meteorite, estimate the age of the
  47. chemistry

    Which of the following is true? A. Group 1 elements are more reactive than the group 2 elements because they have more valence to lose. B.Lithium is the least reactive element in group, because its valence electron is held more tightly than the others in
  48. chemistry

    why does atomic size decrease cross a period? why does atomic size increase down a group?
  49. SCIENCE

    ORDER OF INCREASING ATOMIC SIZE: Cs, Li, and Rb
  50. chemistry

    Rank the following elements by electron affinity, from most positive to most negative EA value: tellurium, bismuth, neon, sodium, iodine i tried Te, Bi, Na, I, Ne and it was incorrect.
  51. Science

    Does Francium or Cesium have the greatest atomic radius? Thank you
  52. chemistry

    Based on position in the periodic table and electron configuration, arrange these elements in order of decreasing E_ i1
  53. Chem

    Na P Ca Br arrange in incresing order of atomic size
  54. Chemistry Help!!!!

    for each of the following pairs of elements, give the correct molecular formula, explain how you arrived at this answer( you may use the Bohr model notation, or the orbital model notation, or explain linguistically) and note whether the bonding is covalent
  55. Chemistry

    Rank the ions in order of decreasing size. Sr2+, Ba2+, Cs Cs>Ba>Sr
  56. chemistry

    Evaluate the statement. Bromine (Br) is a halogen. Given the information in the statement, what can be inferred as true about bromine? bromine tends to form covalent bonds when in a chemical reaction with metals bromine has seven electrons and seven
  57. CHEMISTRY

    a gas mixtuer consists of equal masses of methane(molecular weight 16.0) and argon (atomic weight 40.0) if the partial pressure of argon is 26.6 kPa, what is that of methane in the same units? 10.7 26.7 66.7 34.1 I am going with 26.7 Do you agree and why
  58. chemistry

    Dr bob can you help with my last question for tonights home work please A gas mixture consists of equal parts of methane(molecular weight 16.0) and argon (atomic weight40.0). if the partial pressure of argon is 26.6 kPa what is that of methane in the same
  59. Science help

    For each of the following what type of smallest particle would exist? explain your reasoning? a.) strontium B.) CaCl2 C.) CCl4 D.) SO2 E.) helium F.) bromine G.) MgO Thanks :):):):)
  60. 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?
  61. Chemistry

    Radioactive decay is first order in the decaying isotope. For example, strontium-90 contained in fallout from nuclear explosions decays to yttrium-90 and a beta particle. Write the rate law for the decay of strontium-90. Can you please take me step by stem
  62. geometry

    how do you do list the following elements in proper set notation. Place the elements in numerical order within the set. *0*123*4*34* 1
  63. geometry

    List the following elements in proper set notation. Place the elements in numerical order within the set. * 0 * 1 * 123 * 4 * 34
  64. geometry

    List the following elements in proper set notation. Place the elements in numerical order within the set. * 0 * 1 * 123 * 4 * 34
  65. Chemistry

    As you go across the period of the periodic table, you are increasing the atomic number while decreasing the atomic radius, but what causes this trend?
  66. Chemistry

    1) How does the atomic radius change from left to right across a period in the periodic table? A) It tends to decrease*** B)It tends to increase C) It first increases, then decreases D) It first decreases, then increases 2) What is the charge of a cation?
  67. Chemistry

    1) How does the atomic radius change from left to right across a period in the periodic table? A) It tends to decrease*** B)It tends to increase C) It first increases, then decreases D) It first decreases, then increases 2) What is the charge of a cation?
  68. CHEM Periodic Trends

    Each of the statements below attempts to explain why some periodic property varies predictably among elements in the periodic table. Determine if each statement is true or false. Within a family, elements with higher atomic numbers have higher
  69. chemistry

    What mass of cesium bromine must be added to a 0.500 liter of water (d=1.00 g/ml) to produce a 0.981m solution? what are the mole fraction and mass percent of CsBr?
  70. Chemistry

    Arrange the following cations in order of decreasing size :Ra2+,Sr2+,Ca2+,Ba2+.Also explain it.
  71. Science

    What conclusion can be drawn about the relationship between the arrangement of elements on the periodic table and the patterns observed in their priorities? A. Properties of elements are related to atomic numbers. B. Properties of elements are related to
  72. algebra 2

    Apparently i got this wrong, but my teacher is giving me a chance to redo. The question was to put these numbers in decreasing order. _/13, pi, 1.3, -0.7, -8/5 (and i put them in this order) She gave me a 0/2 and said think about how you would place them
  73. Chemistry

    I just need help with this one question, and then once I know how to do the steps, I think can do the others. --- The average atomic mass of argon is 39.95 u. Natural argon contains three isotopes: Ar-36 (35.967 u), Ar-38 (37.962 u)& Ar-40 (39.962 u). If
  74. Final Exam- Honors Physical Science

    how can you determine the number of protons, electrons,neutrons, atomic number, and the atomic mass of an element using the periodic table? Atomic mass is given in the table, as well as the atomic number and atomic mass number. Atomic number is the number
  75. math

    Suppose strontium-90 decays at a rate of 2 percent per year. (a) Write the fraction P of strontium remaining, as function of t, measured in years. (Assume that at time t=0 there is 100 % remaining.) Answer: P(t)=(.98)^t (b) Estimate the half-life of
  76. science

    1) What conclusions can be drawn about the relationship between the arrangement of elements on the periodic table and the patterns observed in their properties? :Properties of elements are related to atomic numbers.*** :Properties of elements are related
  77. science,physics,chemistry

    According to our theory atomic size should increase in groups from top to bottom but in group 13 Aluminium has atomic radius 143 pm and Gallium has atomic radius 135 pm which is less WHY??????
  78. World History

    place the events in calendar order from first to last 1) Nazi-Sovie Pact 2) Attack on Pearl Harbor 3) Annexation of Austria 4) Dropping of atomic bomb in Hiroshima 5) Surrender of France list is order that the event happened
  79. Chemistry

    We did a flame test today to see what substances produce what colors when burned. Can you please explain... Why each of the different elements have a different atomic emission spectrum? Would the flame tests be useful for detecting individual elements
  80. Chemistry

    Which trends are observed when the elements in Period 3 on the Periodic Table are considered in order of increasing atomic number? (1) The atomic radius decreases, and the first ionization energy generally increases. (2) The atomic radius decreases, and
  81. Chemistry

    The standard atom for the atomic masses of all the elements is the atom of carbon which has 6 protons and 6 neutrons (12C) and is assigned the atomic mass of exactly 12. Under this standard, the atomic mass of iron, atomic number 26, is 55.845 u and the
  82. Chemistry

    Of the 3 elements nitrogen , oxygen , and aluminum, what is the atomic number of the one that has the smallest atomic radius?
  83. Chemistry

    Of the 3 elements fluorine, nitrogen, and carbon, what is the atomic number of the one that has the largest atomic radius?
  84. chem1 WORD PROBLEM!!

    lead has an atomic number of 82;iron has an atomic number of 26; and copper has an atomic number of 29.how do the charges of the nuclei of these 3 elements compare?
  85. chemistry

    the longest lived radioactive isotope yet discovered is the beta-emitter tellurium-130.it has been determinded that it would take 2.4 x 10^21 years for 99.9% of this isotope to decay. write the equation for this reaction, and identify the isotope into
  86. Physics

    Bees often work together for the greater good of the hive. Sometimes they can get excess charge on them. Four pairs of bees, which can be represented as identical, conducting spheres, bump into each other in the hive. Rank the bees in the order of the size
  87. physics

    Bees often work together for the greater good of the hive. Sometimes they can get excess charge on them. Four pairs of bees, which can be represented as identical, conducting spheres, bump into each other in the hive. Rank the bees in the order of the size
  88. Sci Plzz See This Post

    Does my poem below have these things "explain why it is where it is on the periodic table, what element(s) it might combine with to make a compound/molecule, and finally, WHY it would interact with that other element" Here is the Poem Below: “What’s
  89. Sci

    Does my poem below have these things "explain why it is where it is on the periodic table, what element(s) it might combine with to make a compound/molecule, and finally, WHY it would interact with that other element" Here is the Poem Below: “What’s
  90. Chemistry

    When you look up the atomic masses of Si and Sn and then find the average and then look up the atomic mass of Ge, what is discovered? does it lend supporting evidence to the periodicity of elements?
  91. Chem

    Order the elements carbon, oxygen and chlorine from the ff: 1) greatest to least according to atomic radius 2) greatest to least according to ionization energy
  92. Chemistry

    A gas mixture consists of equal masses of methane (molecular weight 16.0) and argon (atomic weight 40.0). If the partial pressure of argon is 200. torr, what is the pressure of methane, in torr?
  93. Chemistry

    Arrange the ions Cu2+ Zn2+ Mg2+ and Al 6+ in order of decreasing ability to be reduced and in order of decreasing ability to be oxidized
  94. Chemistry

    The half-life for beta decay of strontium-90 is 28.8 years. A milk sample is found to contain 10.3 ppm strontium-90. How many years would pass before the strontium-90 concentration would drop to 1.0 ppm?
  95. Chemistry(please check my answer)

    The transuranium elements A. are the elements with atomic numbers above 92. *** B. occur in nature. C. are sometimes radioactive. D. all of the above
  96. science-chemistry

    how do the following changes affect the speed of a reaction? a)Increasing the concentration of the reactans. b)Decreasing the temperature. c)Decreasing the partickle size of a solid reactant.
  97. Chemistry

    In the reaction between bromine and sodium, a bromine atom gains an electron. What ion is formed? Is the bromine oxidized, or is it reduced?
  98. PHYSICAL SCIENCE PLEASE HELP REALLY APPRECIATE IT!

    In the reaction between bromine and sodium, a bromine atom gains an electron. What ion is formed? Is the bromine oxidized, or is it reduced? Thank You ^_^
  99. chemistry

    Place these hydrocarbons in order of decreasing boiling point: paraffin : methane: octane: isooctane: ( also known as 2,2,4 trimethylpentane) octadecane:
  100. science

    Mercury is a heavy metal. Using atomic models and the periodic table of elements, explain why it belongs to this category of elements