Chemistry

What is the cause of change over time in a population?O The environment modifies.O All members can mate easily with all other members.O No new members come in or go out.
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Which of the following sites has volcanoes related to subduction? A is on an island arc, B is in the Andes, C is near Hawaii, D is along a mid-ocean ridge.
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Nitrogen gas and hydrogen gas are combined in a reaction to produce ammonia. If 3.0 moles of N2 and 12.0 moles of H2 are present in the mixture, which is the limiting reactant?
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Draw the Lewis structure (including all lone pair electrons) for one isomer of the molecular formula C3H8O.
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What is the percentage composition of soap (C12H35COON)?
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A reaction has a rate constant of 0.0642 sec-1; how long will it take (in minutes) until 0.479 mol/L of the compound is left, if there was 0.502 mol/L at the start? (give answer to 3 decimal places)?
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Write the full ground-state electron configuration for each:(a) Rb (b) Ge (c) Ar
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Mackenzie creates a transverse wave using a rope tied to a tree, as shown in the diagram.Her teacher asks her to change the wave to show a greater energy transfer. What does she do?A. She increases the wavelength of the wave.B. She decreases the amplitude of the wave.C. She increases the amplitude of the wave.D. She decreases the frequency of the wave.
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KI KI has a lattice energy of 649 kJ/mol. 649 kJ/mol. Consider a generic salt, AB AB , where A 2 + A2+ has the same radius as K + , K+, and B 2 B2 has the same radius as I . I. Estimate the lattice energy of the salt AB AB .
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What is the pH of an aqueous solution with the hydronium ion concentration : [H3O+] = 6.3 x 10-6 M ?
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Im trying to find the number of representative particles in 0.4 mol KCL what is my first step?
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Write the symbol for every chemical element that has atomic number less than 14 and atomic mass greater than 23.3 u.
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A certain molecular compound has a solubility in hexane of at . Calculate the mass of that's dissolved in of a saturated solution of in hexane at this temperature. Be sure your answer has the correct unit symbol and significant digits.
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Classify each of the following chemical reaction (check all that apply) : combination, precipitation, single replacement, combustion, double replacement, acid-base, decomposition (1) HI(aq) + NaOH(aq) Nal(aq) + H20(l) (2) CuSO4(aq) + ZnCrO4(aq) ZnSO4(aq) + CuCrO4(s) (3) CH3CH2OH(l) + 302(g) 2CO2(g) + 3H2O(g) (4) NaCl(aq) + AgNO3(aq) NaNO3(aq) + AgCl(s)
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A catalyst can increase the rate of a reaction ________. Select one: a. by increasing the overall activation energy (Ea) of the reaction b. by providing an alternative pathway with a lower activation energy c. by lowering the activation energy of the reverse reaction d. by changing the value of the frequency factor (A) e. All of these are ways that a catalyst might act to increase the rate of reaction.
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Perching birds, such as cardinals, warblers, and robins, live in trees. Suppose a developer cuts down all of the trees in an area to build a housing subdivision. What would most likely happen to the perching birds living in that ecosystem? A. The perching birds would begin building their nests on the ground. B. The perching birds would be forced to migrate to another area. C. The perching birds would all starve and subsequently die out. D. The perching birds would stop reproducing until new trees grew in the area.
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The table below shows some of the stars in our galaxy and their numbers of light years from the Sun.StarLight Years from the SunChara27.3 light yearsTau Ceti11.9 light yearsZeta Leporis70.2 light yearsEpsilon Reticuli59.5 light yearsWhich star is the closest distance to the Sun? A. Tau Ceti B. Epsilon Reticuli C. Zeta Leporis D. Chara
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The biopsychosocial perspective, compared with the perspectives of Freud, Jung, and Rogers, __________.
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The osmotic pressure, , of a solution of glucose is 83.1 atm . Find the molarity of the solution at 298 K. Express the molarity to three significant figures and include the appropriate units.
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To determine the molar mass of a protein, a 0.891 g sample of it is added to 5.00 g of water and the osmotic pressure is measured as 0.179 atm at 22.0C, what is the molar mas of the protein? (The protein is non-ionizing)
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Which contains more molecules, a mole of water or a mole of glucose?
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What does the subscript mean in the chemical formula CO2?
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The charges of a set of isoelectronic ions vary from 3+ to 3-. Place the ions in order of increasing size.
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Which of the following should most favor the solubility of an ionic solid in water? Note: high and low refers to the magnitudes (i.e. the absolute value) of lattice and hydration energiesA. a small lattice energy for the solid and a small hydration energy for its ions B. a small lattice energy for the solid and a large hydration energy for its ions C. a large lattice energy for the solid and a small hydration energy for its ions D. a large lattice energy for the solid and a large hydration energy for its ions
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