Posts by danny123

Total # Posts: 39

  1. science

    is a dishwasher a wheel and axle
  2. science

    What are examples of inclined planes in the kitchen?
  3. Algebra 2

    How do solve (x^2/3) +1 = 9?
  4. Algebra 2

    Write x in terms of e: ln x^2 = 8. Is it e^2√2 = x?
  5. Chemistry

    Given the balanced equation representing a reaction: Cao(s) + CO2(g) ---> CaCO3(s) + heat What is the total mass of CaO(s) that reacts completely with 88 grams of CO2(g) to produce 200. grams of CaCO3(s)? I don't understand what you have to do.
  6. Chemistry

    Which quantity of particles is correctly represented by the formula H2SO4? Explain.
  7. Chemistry

    A rigid cylinder contains a sample of gas at STP. What is the pressure of this gas after the sample is heated to 410 K? a. 1.0 atm b. 0.50 atm c. 0.67 atm d. 1.5 atm Explain how you get the answer.
  8. Chemistry

    but can't you simplify that to CH3
  9. Chemistry

    why
  10. Chemistry

    What is the empirical formula of a compound that has a carbon-to-hydrogen ratio of 2 to 6? Is it CH3?
  11. Chemistry

    The gram-formula mass of NO2 is defined as the mass of one mole of a. one mole of NO2 b. one molecule of NO2 c. two moles of NO d. two molecules of NO Explain why.
  12. Chemistry

    thanks
  13. Chemistry

    A sample of gas confined in a cylinder with a movable piston is kept at constant pressure. The volume of the gas doubles when the temperature of the gas is changed from a. 200. K to 400. K b. 200. C to 400. C How do you know if it's kelvin or celsius? k= c + 273, by the way.
  14. English

    What kind of figurative language is in "She pulled in her horizon like a great fish-net,". Is it both a hyperbole and a simile?
  15. Chemistry

    thanks!
  16. Chemistry

    At STP, a 7.49-gram sample of an element has a volume of 1.65 cubic centimeters. The sample is most likely (1) Ta (3) Te (2) Tc (4) Ti How do you get the answer?
  17. Chemistry

    What is the only positive ion found in H2SO4(aq)? a. ammonium ion b. hydronium ion c. hydroxide ion d. sulfate ion The answer's b, but I don't understand why.
  18. Chemistry

    thanks
  19. Chemistry

    Why, in terms of atomic structure, is the radius of an Na atom larger than the radius of an Na+ ion?
  20. Chemistry

    In calcium, the electron configuration is 2-8-8-2. Why does the 3rd level have more energy than the 2nd if they're both 8?
  21. Chemistry

    Which element requires the least amount of energy to remove the loosely held electron from a gaseous atom in the ground state? a. bromine b. calcium c. sodium d. silver How do you know?
  22. Chemistry

    How is the chemical bonding in Na3PO4 both covalent and ionic?
  23. Chemistry

    Magnesium nitrate contains chemical bonds that are ? 1. Covalent Only 2. Ionic Only 3. Both Covalent And Ionic 4. Neither Covalent Nor Ionic The answer is 3, but I don't know why. How does NO3 even bond?
  24. Chemistry

    Which formula represents a molecular compound? (1) Kr 3) N2O4 (2) LiOH (4) NaI How do you know?
  25. Chemistry

    The chemical bond between which two atoms is most polar? (1) C–N (3) S–Cl (2) H–H (4) Si–O How do you find out?
  26. Global History

    Was the middle class satisfied with the steps Napoleon took to restore order to France?
  27. Algebra 2

    How do you simplify (x^3+x^2-x-1)/(x^3-x^2-x+1)?
  28. Algebra 2

    When you simplify 5^-1(3^-2*2^-3), is it 1/360?
  29. Chemistry

    thanks
  30. Chemistry

    An atom contains a total of 29 electrons. When the atom is in the ground state how many principle energy levels will contain electrons? a: 1 b: 2 c: 3 d: 4 How do you figure this out?
  31. Chemistry

    What is the total number of principal energy levels or shells in an atom with an atomic number of 30? and why? (1) 3 (2) 4 (3) 5 (4) 6
  32. Chemistry

    thanks
  33. Chemistry

    Compare the amount of heat required to vaporize a 200.-gram sample of H20(L) at its boiling point to the amount of heat required to melt a 200.-gram sample ofH20(s) at its melting point.
  34. Algebra 2

    When you solve 6 + 5|2r-3|≥ 4, is the answer r ≥ 13/10 and r ≤ 17/10?
  35. Algebra 2

    thanks
  36. Algebra 2

    so t=0 or t=-1 or t=1, and the solution set is {0,-1,1}?
  37. Algebra 2

    Is this how you solve t^3 - t = 0? t(t^2-1)=0 t(t-1)(t-1)=0 t=0 or t=1 {0,1}
  38. Algebra 2

    the solution set
  39. Algebra 2

    When you solve t(t+1)(t-2)=0, is the solution {0, -1, -2}?