Master Chemistry with Fun Quizzes & Brain Teasers!

what is the formal charge on phosphorus in a lewis structure for the phosphate ion that satisfies the octet rule?
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a compound containing chromium and silicon contains 73.52 mass percent chromium. determine its empirical formula.
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what is the net ionic equation for the reaction that occurs when you mix aqueous solutions of khco3 and hc2h3o2 ?
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what energy, in megaelectron volts, is released in this decay? the mass of the daughter nuclide is 231.036298 u.
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ion channels: a. only open in response to a signal of some kind. b. require input of energy in order to function
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the aerobic decomposition of biomass produces significant quantities of methane. question 15 options: true false
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the electronegativity is 2.1 for h and 1.8 for si. based on these electronegativities, sih4 would be expected to
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is active transport required to move molecules from high to low concentration or low to high concentration? why?
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consider the data showing the initial rate of a reaction at several different concentrations of a. what is the order of the reaction? write a rate law for the reaction, including the value of the rate constant, k.
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what is the wavelength of the photon emitted when the electron in a hydrogen atom makes a transition from the n
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the bond angle is the angle between multiple choice question. a) the sigma and pi bonds in a double bond. b) the nucleus and the bonding electrons. c) two terminal atoms and the central atom. d) the orbitals of a bonding atom.
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element x has successive ionization energies of 738 kj/mol, 1451 kj/mol, and 7733 kj/mol. element z has successive ionization energies of 1000 kj/mol, 2252 kj/mol, and 3357 kj/mol. what are the possible identities of x and z?
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which of the following concerning molecular geometry and dipole moments is correct? all molecules with polar bonds have a permanent dipole moment. all square planar molecules are nonpolar. all linear molecules are nonpolar. only molecules with polar bonds may have a permanent dipole moment. a molecule with nonpolar bonds could have a permanent dipole moment, depending on the molecular geometry.
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What mass of steam at 100C must be mixed with 150g of ice at its melting point, in a thermally insulated container to produce water of 50C?
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Identify whether the atom or ion in each equation shows oxidation or reduction. cu2 e cu cu2 is fe fe3 3efe is f e ff is 2l l2 2el is 2h 2e h2h is
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Describing Enthalpy ChangesWhat term describes the overall energy change inthe substance portrayed in the graph at right?endothermicexothermicTemperature vs. Heat Added120st10080Temperature,degreesCelsius604020A-20 +B50Heat added, kJE100
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The diagram shows changes of state between solid, liquid, and gas. The atoms of a substance gain energy during a change of state. Before the change, the atoms are close together and cannot slide past one another. After the change, the substance can fill its container.A diagram has a triangle at center with gas on top, liquid on bottom right, solid on bottom left. An arrow from gas to liquid is labeled O, and an arrow from liquid to gas is labeled N. An arrow from solid to liquid is labeled P, and an arrow from liquid to solid is labeled Q. An arrow from solid to gas is labeled L, and an arrow from gas to solid is labeled M.Which arrow represents the change of state described above?
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The periodic properties of elements are directly related to the A: group position, B: effective nuclear charge , C: energy levels ,D: Atomic Finite boundaries. ,choose the correct answer
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consider the methane molecule. what is the central atom? enter its chemical symbol. how many lone pairs are around the central atom? what is the ideal angle between the carbon-hydrogen bonds? compared to the ideal angle, you would expect the actual angle between the carbon-hydrogen bonds to be ... (choose one)
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how many o atoms are in ammonium acetate? how many o atoms are in ammonium acetate? 5 2 1 3 none of the above
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acid strong or weak? species present at 10-6 mol/l or greater when dissolved in water strong weak strong weak
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which type of substance is fast acting, either immediately suffocating the victim or causing massive burning?
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if a 10 ml solution of 0.5 m lead (ii) nitrate reacts with excess ki, how many gram of precipitate will form?
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what volume (in liters) would the gas occupy at a pressure of 1.11 atm if its temperature remained unchanged?
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