1. SCIENCE

    What is the chemically combined substance of a hydrogen atom and a helium atom. please help me because i really don't know this is confusing really please and thankyou Hydrogen atoms don't normally combine with helium atoms. In fact, helium atoms don't
  2. chemistry

    Which statement correctly describes an atom of the element helium? A. An atom of helium has its valence electrons in it's first energy level. B. An atom of helium most similarly behaves like an atom of hydrogen since it is in the same period. C. An atom of
  3. physics

    One atom of Deuterium weighs 2.013553AMU. One atom of Helium weighs 4.002602AMU. In nuclear fusion, the process which powers the Sun and all other stars, 2 atoms of Deuterium are combined to form 1 atom of helium. Calculate the energy released by one such
  4. Chemistry/reading

    Although Rutherford's model was highly successful, scientists realized that it was incomplete. For example, hydrogen atoms contain one proton, and helium atoms contain 2, yet a hydrogen atom has only 1/4 the mass of a helium atom. I'm not comprehending
  5. Physics

    A helium-4 atom falls from a height h into a tank of gaseous helium atoms at 300 K. What is h in meters if the temperature of the helium atoms remains at 300 K after the falling atom enters the tank? Details and assumptions The acceleration of gravity is
  6. Chemistry

    A helium atom has a smaller atomic radius than the hydrogen atom. Explain why.
  7. physics

    The nucleus of a hydrogen atom is a single proton, which has a radius of about 1.0 10-15 m. The single electron in a hydrogen atom normally orbits the nucleus at a distance of 5.3 10-11 m. What is the ratio of the density of the hydrogen nucleus to the
  8. physics

    An ionized helium atom has a mass of 6.6*10^-27kg and a speed of 4.4*10^5 m/s. The atom moves perpendicular to a 0.75-T magnetic field on a circular path of radius 0.012m. Determine whether the charge of the ionized helium atom is +e or +2e. Can anyone
  9. chem

    one atom of silicon can properly be combined in a compound with A. one atom of chlorine B. two atoms of oxygen C. three atoms of hydrogen D. four atoms of calcium B. two atoms of oxygen (as in SiO2.. quartz and sand) Ther is also a compound SiO. It is used
  10. physics

    The nucleus of a hydrogen atom is a single proton, which has a radius of about 1.0 10-15 m. The single electron in a hydrogen atom normally orbits the nucleus at a distance of 5.3 10-11 m. What is the ratio of the density of the hydrogen nucleus to the
  11. chemistry

    The chemical substance in natural gas is a compound called methane. Its molecules are composed of carbon and hydrogen and each molecule contains four atoms of hydrogen and one atom of carbon. In this compound, 0.33597g of hydrogen is combined with 1g of
  12. Physics

    What happens after an elastic collision between a hydrogen atom at rest and a helium atom moving 150 m/s? Which direction will the particle move after the collision? Which particle will have a higher speed after the collision? What happens when a neutron
  13. Science

    When two hydrogen atoms bond with one oxygen atom to form water, what happens to the electrons? A. Each hydrogen atom donates its electron to the oxygen atom. B. The oxygen atom donates an electron to ach hydrogen atom. C. A pair of electrons is shared at
  14. Science

    When two hydrogen atoms bond with one oxygen atom to form water, what happens to the electrons? A. Each hydrogen atom donates its electron to the oxygen atom. B. The oxygen atom donates an electron to ach hydrogen atom. C. A pair of electrons is shared at
  15. biochemistry

    Which statements about hydrogen bonds are correct? 1) Hydrogen bonds are the interaction between a hydrogen atom bonded to an electronegative element and the lone pair of electrons on a nearby electronegative atom. 2) The atom to which the hydrogen atom is
  16. physical science

    can two or more elements be combined chemically to make a new element? Explain. My answer: No, it becomes a compound which is a substance combined of two or more elements chemically combined not sure if correct - I am doing the review and not sure of a few
  17. physics

    In the Sun, an ionized helium atom makes a transition from n =6 state to the n = 2 state, emitting a photon. Can that photon be absorbed by hydrogen atoms present in the Sun? If so between what energy states will the hydrogen atom jump?
  18. Chem---DrBob222

    Calculate the oxidation # for each atom in the molecule below. Can you help me with the rest. Thank you!!! H H H H / / / / H -- C ---C ===C ----N .. / / H H Group # # of E Oxidation # H 1 0 1 x 7 = 7 C 4 7 C 4 C 4 N 5 3 H atom attached to first C atom. 1 H
  19. Chem

    Which of the following statements is (or are) true? I Hydrogen bonds occur between two hydrogen atoms. II Hydrogen bonding occurs between a hydrogen atom and an oxygen atom within a molecule. III Hydrogen bonding requires a molecule containing a large
  20. Science Help!

    When two hydrogen atoms bond with one oxygen atom to form water, what happens to the electrons? A. Each hydrogen atom donates its electron to the oxygen atom B. The oxygen atom donates an electron to each hydrigen atom C. A pair of electrons is shared at
  21. Chemistry

    which atom has the least attraction for the electrons in a bond between that atom and an atom of hydrogen? (1) carbon (2)nitrogen (3)oxygen (4) fluorine
  22. Physics

    The hydrogen atom contains 1 proton and 1 electron. The radius of the proton is approximately 1.0fm femtometers, and the radius of the hydrogen atom is approximately 53 pm (picometers). - Calculate the volume of the nucleus and the volume of the atom for
  23. physics

    The distance between a hydrogen atom (m = 1.0u) and a chloride atom (m = 35.5u) in the HCl molecule is 1.27×10-10m. How far from the hydrogen atom is the center of mass of the molecule?
  24. physics

    A water (H2O) molecule consists of two hydrogen atoms and one oxygen atom. The oxygen atom is located at the origin. One hydrogen atom is between the positive x-axis and positive y-axis and the other hydrogen atom is between the negative x-axis and the
  25. Chemistry

    Explain how the formulas for H2O and NaCl provide different information about the composition of these two compounds. What I think: For every 1 atom of oxygen, there are 2 atoms of hydrogen. For every one atom of sodium there is one atom of chlorine.
  26. Chemistry

    Why is an alpha particle written as a helium (He) nucleus? A. An alpha particle has two protons and two neutrons; it is essentially the nucleus of a helium atom. B. Helium is a common element that is often present in small forms; the alpha particle was
  27. Zoology

    Can you rank these from the smallest to the largest? Heart carbon atom sodium atom electron nucleotide tundra mitochondria glucose molecule fungal cell hydrogen atom
  28. Chemistry

    Does every neutral helium atom in the universe have the same set of absorption lines as every other neutral helium atom (with the same atomic mass)?
  29. chemistry

    When will hydrogen bonding occur?Give an example of liquid other than H2O in which this type of force is important. In order for a hydrogen bond to occur there must be both a hydrogen donor and an acceptor present. The donor in a hydrogen bond is the atom
  30. Chemistry

    Is there someone out there that can tell me if I answered this right or if I need to study some more? Thanks What is it that makes water such a good solvent for polar substances? Why is it called the universal solvent? Water is such a good solvent for
  31. Physics

    Could someone help me with these questions. . . please 1. How does Rutherford’s model of the atom account for the back – scattering of alpha particles directed at the gold leaf 2. The higher the energy level occupied by an electron in the hydrogen
  32. help SCIENCE help

    What is the difference between an atom, compound, and mineral??????? Please help, Thanks Atom= matter in the form of small units Compound= elements chemically combined Mineral= inorganic nutrients that regulate many chemicals in the body for definition of
  33. Chemistry

    1.) The average velocity of Cl(2) molecules is 2.50 x 10^3 m/sec at a temp of 25 C therefore the average velocity of helium atoms is ?? [ i got the answer 5.94 x 10^2 m/Sec is that right] 2.) A gas is allowed to expand from 1.5 : to 12.5 L against a
  34. chemistry

    Select all substances with an acceptor atom that can hydrogen bond to a hydrogen atom that is part of a polar covalent bond. I2 diiodine HI hydrogen iodide KrF4 krypton tetrafluoride O2 dioxygen C6H6 benzene HCl hydrogen chloride None
  35. physics

    The higher the energy level occupied by an electron in the hydrogen atom, the larger the atom. The diameter of the atom is proportional to n2, where n=1 labels the lowest, or “ground” state, n=3 is the third state, and so on. If the atom’s diameter
  36. Physics

    The higher the energy level occupied by an electron in the hydrogen atom, the larger the atom. The diameter of the atom is proportional to n2, where n=1 labels the lowest or “ground” state, n=3 is the third state, and so on. If the atom’s diameter is
  37. Physics

    The higher the energy level occupied by an electron in the hydrogen atom, the larger the atom. The diameter of the atom is proportional to n^2, where n=1 labels the lowest or "ground" state, n=3 is the thrid state, and so on. If the atom's diameter is 1 x
  38. physics

    The higher the energy level occupied by an electron in the hydrogen atom, the larger the atom. The diameter of the atom is proportional to n2, where n = 1 labels the lowest, or "ground" state, n = 2 is the second state, n = 3 is the third state, and so on.
  39. Physics

    Can someone help me with this, i have started it but cant get it to work out. The higher the energy level occupied by an electron in the hydrogen atom, the larger the atom. The diameter of the atom is proportional to n2, where n=1 labels the lowest, or
  40. college chemistry

    According to the Bohr theory of the hydrogen atom, what is the minimum energy (in J) needed to ionize a hydrogen atom from the n = 2 state?
  41. chem

    According to the Bohr theory of the hydrogen atom, what is the minimum energy (in J) needed to ionize a hydrogen atom from the n = 2 state?
  42. Biology

    Would an atom of silicon form an ionic bond with an atom of helium? Why or Why not?
  43. physics

    In ammonia (NH3) molecule, the three hydrogen atoms form an equilateral triangle, the distance between the centers of the atoms being 16.28x10^-11 m, so that the center of the triangle is 9.40x10^-11 m from each hydrogen atom. The nitrogen atom is at the
  44. Chemistry

    The single proton that forms the nucleus of the hydrogen atom has a radius of approximately 1.0 x 10^-13 cm. The hydrogen atom itself has a radius of approximately 52.9 pm. What fraction of the space within the atom is occupied by the nucleus.
  45. Science

    1. How is a model of an atom different from a real atom? A. A model of an atom is not as big as an actual atom. B. A model of an atom is the same as a real atom. C. A model of an atom is more complex than a real atom. D. A model of an atom is not as small
  46. Science

    Hello van some one show me how to draw a dot and cross diagramm for 1 lithium atom and 1 fluorine atom(Lif) and also a diagram for 1 magnesium atom and 1 oxygen atom (MgO) Thankyou Paul.
  47. CHEMISTRY

    Select all substances with a hydrogen atom that would participate in hydrogen bonding with an appropriate acceptor atom. (CH3)2CO(acetone), CO(carbon monoxide), S8(octasulfur), CHClCHCl (cis-1,2-dichloroethene),CF3CF3(hexafluoroethane),CH3COCH3CH2
  48. CHEMISTRY

    Select all substances with a hydrogen atom that would participate in hydrogen bonding with an appropriate acceptor atom. (CH3)2CO acetone CO carbon monoxide S8 octasulfur CHClCHCl cis-1,2-dichloroethene CF3CF3 hexafluoroethane CH3COCH3CH2 methylethylketone
  49. Physics

    The allowed orbits for the electron around the nucleus of the hydrogen atom are explained by de Broglie as ... a. Quantized values for the total energy of the electron in the atom b. Quantized values for the angular momentum of the electron in the atom c.
  50. Science

    Atom building game board has 17 protons, 18 neutrons, and 18 electrons. *What is the atom that's represented on the game board. *What is the total charge on this atom? *What is the mass # of this atom? *What do you call an atom that different #'s of
  51. physics

    a helium atom is in one of its single states.one of the electrons is in an p-state and the other a D-sate.the atom is placed in a magnetic field,B,of strengh 3 tesla. sketch a diagram showing the degenerated states and all permissible transition from
  52. integrated chemistry and physics

    In a water molecule, two hydrogen atoms bind to one oxygen atom. How many lone pairs of electrons will be shown around each hydrogen atom in the Lewis structure of water?
  53. physics

    Please help me answer the question below and also show equations and steps of how you came to your answer. Thank you 1. The electron in a hydrogen tom is in the first excited state, when the electron acquires an additional 2.86eV of energy. What is the
  54. Physics

    Please help me answer the question below and also show equations and steps of how you came to your answer. Thank you 1. The electron in a hydrogen tom is in the first excited state, when the electron acquires an additional 2.86eV of energy. What is the
  55. Physics

    A doubly charged helium atom (mass = 6.68 x 10-27 kg) is accelerated through a potential difference of 3.00x 103 V. What will be the radius of curvature of the path of the atom if it is in a uniform 0.410 T magnetic field?
  56. Science

    The thermonuclear process in solar and less massive stars which produces one atom of helium from four of hydrogen is the?
  57. Physics (help steve)

    A helium ion is at rest in a laboratory when it is put in an electric field of E=2 N/C. An infrared light, of wavelength 2000 nm, is directed towards the ion. The ion is moving towards the source of radiation. After what time in the laboratory frame in
  58. science

    A hydrogen atom has one proton, two neutrons, and no electrons. Is this atom an ion?
  59. help physics

    A helium ion is at rest in a laboratory when it is put in an electric field of E=2 N/C. An infrared light, of wavelength 2000 nm, is directed towards the ion. The ion is moving towards the source of radiation. After what time in the laboratory frame in
  60. Astronomy

    Mass of the Sun = 1.989 x 10^30 kg Mass of Hydrogen Atom = 1.00794 grams If we assume the Sun is made totally of hydrogen, how many hydrogen atoms are contained within the Sun? If the Sun converts hald of these hydrogen atoms into helium over its lifetime
  61. physics

    The electron in a hydrogen atom with an energy of -0.544 eV is in a subshell with 18 states. What is the principal quantum number, n, for this atom? What is the maximum possible orbital angular momentum this atom can have? Is the number of states in the
  62. SCIENCE,PHYSICS

    A helium ion is at rest in a laboratory when it is put in an electric field of E=2 N/C. An infrared light, of wavelength 2000 nm, is directed towards the ion. The ion is moving towards the source of radiation. After what time in the laboratory frame in
  63. Physics Please Answer

    A helium ion is at rest in a laboratory when it is put in an electric field of E=2 N/C. An infrared light, of wavelength 2000 nm, is directed towards the ion. The ion is moving towards the source of radiation. After what time in the laboratory frame in
  64. Chemistry

    For each of the following, enter the number of covalent bonds that the atom can form: (A) One atom of carbon (B) One atom of sulfur (C) One atom of nitrogen with no net charge (D) One atom of nitrogen with positive net charge (E) One atom of oxygen with no
  65. Chemistry

    A photon with a wavelength of 93.8 nm strikes a hydrogen atom, and light is emitted by the atom. How many emission lines would be observed?
  66. Science

    Which electrons in an atom take the most energy, and what are they called? What Kind of diagram is used to show how many of these electrons an atom has? What name is given to the elements with eight outer electrons? Which element belongs to this group,
  67. Chemistry

    Is it possible for the dispersion forces in a particular substance to be stronger than the hydrogen bonding forces in another substance? I get that in general, LD is weaker than H-bonding, but LD does exist is both polar and nonpolar substances and what if
  68. scince

    One molecule of water (H2O) contains two atoms of hydrogen and one atom of oxygen.A hydrogen atom has a mass of 1.0 u and an atom of oxygen has a mass of 16 u, approximately. (a) What is the mass in kilograms of one molecule of water? (b) How many
  69. chemistry

    um, i was wondering what the word is for a substance composed of two or more elements that are chemically combined to form a new substance with different properties. um, i kinda need the answer soon. thanx. :) Kenzie
  70. Physic

    The distance of electron from the nucleus in a hydrogen atom is 5x10^-11m.Estimate the electrical potential energy of atom
  71. Physic

    The distance of electron from the nucleus in a hydrogen atom is 5x10^-11m.Estimate the electrical potential energy of atom
  72. chem

    1. under what circumstances is the molecular geometry around a single central atom the same as the electron group geometry around the central atom? 2.If all of the electron groups around a single central atom are bonding, and the same outer atom is bonded
  73. AP Chem

    Help with these two please. 105. A radioactive metal atom decays (goes to another kind of atom) by emitting an alpha particle (He+2 ion). The alpha particles are collected as helium gas. A sample of helium with a volume of 12.05 mL was obtained at 765 mmHg
  74. math

    water has a chemical formula h2O which means each molecule of water contains two atoms of hydrogen one atom of oxygen if oxygen atom has a mass 16 times as much as the hydrogen one .what are the propotions of oxygen and hydrogen in 2kkg of water
  75. Chemistry

    A hydrogen atom in one of its excited states ha an energy of -1.5129^20 J. What is the frequency of radiation is emitted when the atom relaxes down to its ground state?
  76. chemistry

    determine the end value of n in a hydrogen atom transition if the electron starts in n=2 and the atom absorbs a photon of light with a frequency of 4.57 times 10^14 Hz
  77. Chemistry

    Which atom has the smallest valence p atomic orbital? -Carbon -Nitrogen -Sulfur Why? A. That atom has the highest electronegativity. B. That atom has the fewest number of electrons. C. That atom does not have electrons in p orbitals. D. The valence
  78. CHEMISTRY

    Select all substances with an acceptor atom that can hydrogen bond to a hydrogen atom that is part of a polar covalent bond HCCH ethyne Br2 dibromine H2CCH2 ethene CH3Cl chloromethane CH3CH2CO2H propionic acid OF2 oxygen difluoride
  79. chemistry

    36 colored paper clips (12 each of 3 different colors) 1.Each paper clip represents a single atom. Designate a different color of paper clip to represent atoms of oxygen (O), hydrogen (H), and carbon (C). Makes two molecules each of hydrogen (H2) and
  80. Chemistry

    The sizes and shapes of the hydrogen atom orbitals was revealed through graphical analysis of the corresponding wave functions. These wave functions also predict areas that the electrons have a zero probability of being found. These areas are known as
  81. Chemistry

    The isotopic abundance of naturally occurring hydrogen is as follows: 1H 99.985 atom % 2H 0.015 atom% When H2 gas is formed from naturally occurring hydrogen, what percentages of the molecules have molecular weights of approximately 2, 3 and 4?
  82. chem

    What are the similarities and differences between the hydrogen atom 2s and 3s orbitals? a) What are the similarities and differences between the hydrogen atom 2s and 3s orbitals? b) What are the similarities and differences between the 2s orbital and a 2p
  83. CHEMISTRY PLZ HELP

    Select all substances with an acceptor atom that can hydrogen bond to a hydrogen atom that is part of a polar covalent bond HCCH (ethyne), Br2 (dibromine), H2CCH2 (ethene), CH3Cl (chloromethane), CH3CH2CO2H (propionic acid), OF2(oxygen difluoride)
  84. CHEMISTRY PLZ HELP

    Select all substances with an acceptor atom that can hydrogen bond to a hydrogen atom that is part of a polar covalent bond. HCCH ethyne Br2 dibromine H2CCH2 ethene CH3Cl chloromethane CH3CH2CO2H propionic acid OF2 oxygen difluoride
  85. physics

    Suppose that you are able to decompose water into hydrogen gas and oxygen ga and that ou can capture all of these gases that are produced. knowing that the mass of an oxygen atom is 8 times that of a hydrogen atom, describe how you could determine which of
  86. physics

    A neon atom (m = 20.0 u) makes a perfectly elastic collision with another atom at rest. After the impact, the neon atom travels away at a 55.2° angle from its original direction and the unknown atom travels away at a 51.8° angle. What is the mass of the
  87. Chemistry

    Determine the end value of n in a hydrogen atom transition, if the electron starts in n=4 and the atom emits a photo of light with a wavelength of 486 nm. *The answer given is 2, but I don't know how they got there.
  88. physics

    how do i go about in solving this? A helium atom (mass 4.0 u) moving at 596 m/s to the right collides with an oxygen molecule (mass 32 u) moving in the same direction at 402 m/s. After the collision, the oxygen molecule moves at 445 m/s to the right. What
  89. science

    1.   Which statement is true about the following molecule?  (1 point)The molecule is composed of four atoms.The molecule contains oxygen atoms.The molecule is water.The molecule represents an element. 2.   A(n) _____________ is made up of two or more
  90. Bio

    1. An isotope is an atom of an element that varies in mass number due to variation in the number of: A. atoms. B. protons. C. neutrons. D. electrons. is it C 2, A covalent bond is: A. the attraction that one atom has for another atom. B. the attraction
  91. College Physics 2

    Estimate the magnitude of the electric field strength due to the proton in a hydrogen atom at a distance of 5.29x10^-11 m, the expected position of the electron in the atom.
  92. chemistry

    Determine the ionization energy of a hydrogen atom (in kJ/mol) if the electron is in its ground state. (Hints: Use the Rydberg equation, remember E=hc for a single H atom, and R=109678x10–2nm )
  93. physics/chem

    Calculate the number of coulombs of positive charge in 261 cm3 of (neutral) water. (Hint: A hydrogen atom contains one proton; an oxygen atom contains eight protons.)
  94. chemistry

    Determine the ionization energy of a hydrogen atom (in kJ/mol) if the electron is in its ground state. (Hints: Use the Rydberg equation, remember E=hc for a single H atom, and R=109678x10–2nm–1 )
  95. Science

    I have a question from an old exam that I need help to understand, i'm not sure where to start An electron in an electronically excited hydrogen atom undergoes a transition from a 6d to a 2p orbital, resulting in the emission of a photon. The photon
  96. science

    I have a question from an old exam that I need help to understand, i'm not sure where to start An electron in an electronically excited hydrogen atom undergoes a transition from a 6d to a 2p orbital, resulting in the emission of a photon. The photon
  97. chem

    How much energy is required to ionize a hydrogen atom in its ground (or lowest energy) state? What wavelength of light contains enough energy in a single photon to ionize a hydrogen atom?
  98. Science

    Which of the following statements is not consistent with the results obtained in Rutherford’s gold foil experiment? A. The nucleus of an atom is positively charged. B. The nucleus of an atom contains almost all the mass of the atom. C. Atoms are composed
  99. Chemistry

    Which of the following statements is not consistent with the results obtained in Rutherford’s gold foil experiment? A. The nucleus of an atom is positively charged. B. The nucleus of an atom contains almost all the mass of the atom. C. Atoms are composed
  100. Chemistryy

    Identify the observations of Ernest Rutherford's experiment with the gold foil. Where he experimented on alpha particles and deflection. Check all that apply.... 1) a positive charge is spread equally over the atom 2) THE MAJORity of the space inside the