1. chemistry

    A light green powder is heated in a test tube. A gas is given off, while the solid becomes black. In which classification of matter does the green powder belong? Explain your reasoning.
  2. science

    A light green powder is heated in a test tube. A gas is given off and the solid becomes black. In which classification of matter does the green powder belong? Explain your reasoning.
  3. Chem 100 Lab

    A black solid is heated in a tube that is completely evacuated of air. Hydrogen is added to the tube. An orange powder is formed and water vapor is seen on the outside of the tube. Is the original solid an element or compound? Can you identify the chemical?
  4. Science

    * P is a a black powder, which, when fused with a mixture of potassium hydroxide and potassium nitrate and then treated with water yields a green solution. The green solution turn purple when acidified. -identify P, the green solution and purple solution. -write ionic equation...
  5. chemistry

    A scientist is performing an experiment on a powder. Which of the following is a sign that a chemical change has definitely occurred during his experiment? The powder catches on fire. The powder releases bubbles. The powder heats up. The powder breaks apart into smaller ...
  6. chemistry

    Q: I just did an online chemisty lab for Oxidation States of Manganese and I'm stuck. I have three test tubes that have been prepared as follows: Tube 1- Starting PH 13.82 2 mL of KMnO4 1 mL of NaOH Tube 2- Starting PH 7 2 mL of KMnO4 Tube 3- Starting PH 0 2 mL of KMnO4 1 mL ...
  7. chemistry

    A student adds .137 grams of nickel(II) hydroxide powder to 10.0 L of distilled water at 25C with vigorous stirring. Did all of the powder dissolve? If not, how much powder remains undissolved? If so, how much more powder can be dissolved before a saturated solution is reached...
  8. Chemistry

    Joseph Priestly discovered oxygen when he heated a red powder. This red powder had been prepared by heating mercury in air. a) name th red powder formed when this element is heated in air b) write a word equation to show what happens to this red powder when it is strongly ...
  9. 5 g vial

    A 5 g igal reguires addinng 8.6 ml diluent to get concentration of 250 mg/ml. The powder volume is __ ml a.9.3 b.10.6 c.11.4 d.12.8 Does the powder form a solution or a colloid? IT makes a big difference. In solutions, the sum of the powder volume and the solvent volume seldom...
  10. MATHS

    ROSE USES INSTANT LEMONADE POWDER TO MAKE 7 PITCHERS OF LEMONADE .SHE USES 2/8 CUP OF POWDER FOR EACH PITCHER.WHAT IS THE AMOUNT OF POWDER THAT ROSES USES
  11. Chemistry (again)

    I need help with this question: Suppose you bake two cakes and the the one with twice as much baking powder raises twice as much. Is this proof of the relation between concentration and reaction rate? See I know concentration has an affect on reaction rate but I am not sure if...
  12. ap chemistry

    A powder has a mass of 40.0g. When the powder is added to 30.0mL of water, the total volume is 45.0mL. What is the density of the powder
  13. chemistry

    Why is filter paper a poor material on which to powder a solid before introducing it into a melting tube?
  14. science

    Why is filter paper a poor material on which to powder a solid before introducing it into a melting tube?
  15. Chemistry

    Please can anyone help me with the following: Filter paper is a poor material on which to powder a solid before introducing it into a melting tube. Why? Thank you!
  16. Organic Chemistry

    Please can anyone help me with the following: Filter paper is a poor material on which to powder a solid before introducing it into a melting tube. Why? Thank you!
  17. Math

    Here's a chalenging one that i can't do at all. A deck of cards has 6 yellow, 6 green, and 5 black cards. You pick four cards from the deck. Cards are not returned after they are picked. What's the probability of picking- first not green, second not green, third not black, ...
  18. science (chemistry)

    filter paper is a poor material on which to powder a solid before introducing it into a melting tube .explain why?
  19. science- help needed.

    each statement is false. rewrite each one as a true statement,showing as much scientific understand as possible. 1. light waves travel slower than sound waves. 2.a black object will reflect white light. 3.a translucent object lets no light through. 4.an orange object will ...
  20. English

    The green light is on. Let's walk across. The green light is on. Let's walk across the street. The green light is on. Let's walk across on the crosswalk. The green light is on. Let's walk across from the sidewalk. Are the sentences above all grammatical? If not, would you ...
  21. Organic Chemistry

    Hello! I was looking for some advice on my organic chemistry lab. We were supposed to separate and identify a solid mixed into a liquid. I found and have confirmed my liquid is acetone by distilling it out of the solid. The solid then turned into a whitish powder while in the ...
  22. check/bio!!!!

    okay the question is as follows: Three plants are placed in 3 different terrariums in 3 different light conditions. Plant A is placed in blue light, plant B in green light, and plant C in yellow light. In which case will there be an increase in the oxygen content of terrarium...
  23. physics

    Let's say you're driving in your car, approaching a red light on the Camp Hill Bypass. A black Porsche is stopped at the light in the right lane, but there's no-one in the left lane, so you pull into the left lane. You're traveling at 40 km/hr, and when you're 15 meters from ...
  24. chemistry

    To analyze for barium in an unknown white powder, an excess of sodium sulfate solution was added to a 0.576 g sample of the powder dissolved in water. A white precipitate of BaSO4 was isolated, dried, and found to weigh 0.438 g. What is the mass percent of Ba in the white ...
  25. Chemistry

    A pyrotechnician mixes 280 g of black powder for a firework. Find the amount of oxygen, carbon dioxide, and sulfur dioxide generated when this firework bursts, if the oxidizing agent in the powder is saltpeter. How do I find their amounts?
  26. science- here is the worksheet someone help me

    Smithers thinks that a special juice will increase the productivity of workers. He creates two groups of 50 workers each and assigns each group the same task (in this case, they're supposed to staple a set of papers). Group A is given the special juice to drink while they work...
  27. math algebra 8

    Jim creates mixtures for new candies. His boss gives him 20 pounds of 12% milk powder, and 32 pound of 20% milk powder. How many pounds of 12% milk powder jim uses if Boss wants him make 30 pounds of 18% milk powder for candies. Please help to answer , and formula also thanks
  28. Mathematics

    A shopkeeper mixed coffee powder worth $2.50 per kg with coffee powder worth $3.50 per kg, and sold 20 kg of the mixture at $2.80 per kg. Find the weights of the 2 grades of coffee powder that he mixed together. Explain clearly your steps of solving it.
  29. Biology

    The observed distribution of offspring was: black-red 1,070; black-white 177; green-red 180; green-white 1,072. Based on these data, what is the recombination frequency? A. 86% B. 7% C. 17% D. 14% E. 30% Background Info: In a particular species of mammal, black hair (B) is ...
  30. chemistry

    Determining Chemical Formulas? This was on my test a few days ago for Basic Chemistry, I received 8/20 and I'd really like to see how to work these problems out. *PLEASE SHOW WORK*. Their are four parts to this, If anyone could answer all four with easy explanations and shown ...
  31. Chemistry

    1. Tube # 3: (a) It started out as purple, and turned into green. (b) No precipitate was noticably formed. Tube #4: (a) This tube was purple, and turned into white. (b) A brown precipitate was formed after adding 1 mL of NaHSO3. Tube #5: (a) This tube was also purple, but then...
  32. Chemistry

    Purple light in the visible region of the electromagnetic spectrum has a shorter wavelength than does the green region of the spectrum. Which of the following can you conclude? Is it: a)a photon of purple light has a higher frequency than does a photon of green light or b) ...
  33. Math Prob/solving

    As Frank drives to work he has to pass through three lights. The probability that any light is green is 39%. Estimate the probability that exactly two lights will be green. Use the following list of digits which was taken from a table of random numbers. In each pair of digits...
  34. Basic Chemistry (Science)

    Determining Chemical Formulas? This was on my test a few days ago for Basic Chemistry, I received 8/20 and I'd really like to see how to work these problems out. *PLEASE SHOW WORK*. Their are four parts to this, If anyone could answer all four with easy explanations and shown ...
  35. Chemistry

    I need another hypothesis: Mom and I were baking a cake for my brother's birthday. We didn't have any baking powder. The recipe said to add one teaspoon of baking powder to the cake batter. Since that's such a small amount we baked the cake anyway. We were very disappointed ...
  36. Physics

    A blue car pulls away from a red stop-light just after it has turned green with a constant acceleration of 0.2 m/s2. A green car arrives at the position of the stop-light 7.5 s after the light had turned green. What is the slowest constant speed which the green car can ...
  37. physics

    A blue car pulls away from a red stop-light just after it has turned green with a constant acceleration of 0.2 m/s2. A green car arrives at the position of the stop-light 7.5 s after the light had turned green. What is the slowest constant speed which the green car can ...
  38. basic mathematics

    ii) A box contains 10 white, 7 black and 3 green balls. 2 balls are drawn at random. Find out the probability that: a) both are white b) one is white and another is green c) one is black and another is green
  39. Juba Day SS

    ii) A box contains 10 white, 7 black and 3 green balls. 2 balls are drawn at random. Find out the probability that: a) both are white b) one is white and another is green c) one is black and another is green
  40. Absorption spectra of pigments

    On the graph light absorption in % vs wavelength, how come the color of chlorophyll is green? Since this is an absorption spectra, isn't it supposed to absorb blue and red and not green? Rather, it reflects green??? How would the graph be different if it is a reflection ...
  41. Science

    Suppose that you heated a sample of a hydrated ionic compound in a test tube. What might you expect to see inside the test tube, near the top of the test tube? Explain please i really am stumped on this question...
  42. Physical Science

    In which of these cases does a ripe banana apear black, red light/green light or blue light? Why?
  43. Chemistry

    This question refers to spectroscopy. So why are certain colors used in this experiment? For example, why would a yellow light be used instead of a green light? And if I were to use a green light instead of a yellow light, would absorbance values be higher or lower?
  44. Biology

    Plz i need help. Plants are green because the pigments in plants reflect green light. Blue and red light give them the most energy to power photosynthesis. You are conducting an experiment to see how different colors of light affect the growth of plants. You place three small ...
  45. Chemistry 106

    What are the elements used to make the ingrediants of each category (the same element may be listed in several categories, but a maximum of once in each of the 6 categories, no matter how many different ingrediants it may be in)? **name of the element with the symbol and ...
  46. Math

    ceftriaxone (rocephin) is a dry powder antibiotic that must be reconstituted for use. the label states that to create a 100 mg/ml solution, 4.8 ml must be added to a 500mg vial. what is the powder volume. I am not sure what formula to use for this problem. How do I go about ...
  47. English

    1. I have seven balls. One is white, another is black, a third is blue, a fourth is green, a fifth is brown, a sixth is pink, and the other is orange. (Is this sentence grammatical and commonly used? 2. I have two balls: One is green and the other is yellow. 3. I have two ...
  48. science!

    this question is not a question but 20 questions. i appreciate if you review all my answers, but i wont provide an answer for the last question (most probably since i didn't finish answering it or typing it out since i only have an hour to do that). now, let's get started. ...
  49. Math/dilution

    A powder concentrate contains 2% w/w of active ingredient. What would be the percentage concentration (w/v) of the resultant solution after a 5-g packet of powder is dissolved in enough water to make 1 quart of solution?
  50. Science, Astrenomey

    This is my theory, read well if you wish to know the truth: according to the big bang, there is a equal amount of anti-matter to the matter, BUT nearly all that matter is missing! In this theory there was NO anti-matter when the earth was made. anti-matter is made when ...
  51. College Physics

    A cyclist is at rest at a traffic light. When the light turns green, he begins accelerating at 2.56 m/s2. How far does he go after the light turns green until he reaches a cruising speed of 10.88 m/s?
  52. physics

    A cyclist is at rest at a traffic light. When the light turns green, he begins accelerating at 2.13 m/s2. How many seconds after the light turns green does he reach a cruising speed of 5.05 m/s?
  53. Science

    A green leaf is reflecting a. no light b. red light c. green light d. all light C
  54. chem

    Ca(H2PO4)2 and NaHCO3 are ingredients of baking powder which react with each other to produce CO2, thereby causing dough or batter to rise: Ca(H2PO4)2 (s) + NaHCO3 (s) -----> CO2 (g) + H2O (g) + CaHPO4 (s) + Na2HPO4 (s) (unbalanced) If the baking powder contains 39 % NaHCO3...
  55. AP Physics B

    A soap bubble of index of refraction 1.43 strongly reflects both the red and the green components of white light. What minimum film thickness allows this to happen? (In air,the wavelength of red light is 703 nm, of green light 502.143 nm.) Answer in units of nm
  56. math

    a bag contains 6 white 2 black and 10 green marbles if a marble is selected at random find the probability that it is green
  57. phys

    A motorist is driving at 20m/s{\rm m/s} when she sees that a traffic light 200m{\rm m} ahead has just turned red. She knows that this light stays red for 15s{\rm s} , and she wants to reach the light just as it turns green again. It takes her 1.0s{\rm s} to step on the brakes ...
  58. biology

    I have another experiment that I am not clear about the results. Any help? Put water, hydrogen proxide, and manganese dioxide powder in test tube, see what happens. Then put sand in the mixture. Results? Then,put liver in it. What happens? Thanks for helping.
  59. Science

    I have 2 questions. 1.) Is there a powder that just contains insoluble fiber. I know that Benifiber and many other products contain soluble fiber or both soluble and insoluble fiber. But for the experament I have put together i need an insoluble fiber powder ONLY! I have not ...
  60. biology

    A rock covered with green spots is placed on a screen in a test tube above some bromothymol blue solution; after several hours, the solution remains blue. What can you conclude form this experiment? AFter doing research, I found out that bromothymol solution is a blue liquid ...
  61. Chemistry

    Some solid calcium oxide in a test tube picks up water vapor from the surrounding to change completely into solid calcium hydroxide. An observed total initial weight (calcium oxide + test tube) f 10.860g goes eventually to 11.149g. What is the weight of the test tube?
  62. Aluminum powder Separation

    We have large quantities of powder containing 40 % alu, 23 % of Si metal , 27 % of Zr metal and other FEO2, CAO,Mg. 0 to 200 µ 200 000 Tons available How is possible to separate it ?
  63. physics

    Green light has a wavelength of 4.96 10-7 m and travels through the air at a speed of 3.00 108 m/s. Calculate the period of green light waves with this wavelength. s What is the frequency? Hz
  64. math

    A traffic light follows the pattern green, yellow, red for 55, 5, and 20 seconds, respectively. What is the probability that the driver approaching this light will find it green or yellow?
  65. physics

    Green light has a wavelength of 4.96 10-7 m and travels through the air at a speed of 3.00 108 m/s. Calculate the period of green light waves with this wavelength. s What is the frequency? Hz
  66. Algebra help??!!

    I'm really confused with sets, could someone please check my answer?? I just really don't want to get it wrong... You have two boxes of colored pens, The first box contains a red pen, a blue pen, and a green pen, The second box contains a yellow pen, a red pen, and a black pen...
  67. Chem

    Solid ferric nitrate and aqueous sodium hydroxide are combined with water in a test tube. A brown to red precipitate forms in the test tube. Write a complete chemical reaction that accounts for the formation of the solid.
  68. algebra

    A TRAFFIC LIGHT IS RED FOR 38 SECONDS YELLOW FOR 10 SECONDS AND GREEN FOR ONE MINUTE AND TWELVE SEONDS. IN A CONSTANTLY REPEATING CYCLE, WHAT IS THE PROBABILITY THAT AT THE MOMENT A PASSING PEDESTRIAN GLANCES AT IT, THE LIGHT WILL BE GREEN
  69. math

    In a bag there are red, green, black,and white marbles. If there are 6 red, 8 green, 4 black, and 12 white and one marble is to be selected at random, what is the probability it will be white? I don't know how to solve these.
  70. Chem

    Classify each of theses changes as a positive or negative change in entropy of a sample of this green gas. A) chlorine gas condense to a liquid = - B) chlorine gas is heated in a container= + C) chlorine gas deposits on a cold surface= -
  71. Math

    A bag of marbles contains only green and red marbles. All of the marbles are the same size. If the probability of selecting a green marble is 1/2. Which is most likely to be the number of green and red marbles in the bag? A.2 green 4 red B.4 green 4 red C.2 green 1 red D.1 ...
  72. Chemistry

    Green Light has a frequency of about 6.00 * 10^14 s^-1. What is the energy of the green light?
  73. physical science

    Joe baked a cake for his mother's birthday. When he removed the cake from the oven, Joe noticed that the cake had not risen. Joe guessed that the baking powder he had used was too old. He designed the following experiment to test his idea. Joe prepared two cakes ¡V one using ...
  74. science

    Destiny is using a nutrient solution to use in her garden.She places the powder in a watering can.Then she adds the water.Which would dissolve the powder the fastest? A.SHAKING THE CAN VIGOROUSLY B.STIRRING THE SOLUTION SLOWLY C.TILTING THE CAN CAREFULLY FROM SIDE TO SIDE D....
  75. Science

    Destiny is using a nutrient solution to use in her garden.She places the powder in a watering can.Then she adds the water.Which would dissolve the powder the fastest? A.SHAKING THE CAN VIGOROUSLY B.STIRRING THE SOLUTION SLOWLY C.TILTING THE CAN CAREFULLY FROM SIDE TO SIDE D....
  76. propability

    Lorenzo has a jar with 21 green olives and 15 black olives in it. If he takes two olives out of the jae with replacement,what is the probability that the first olive will be black and the second olive will be green?
  77. Chemistry

    If I heated NaNO3, would there be yellow gas inside the test tube?
  78. Chemistry

    Some solid CaO in a test tube picks up water vapor from the surroundings to change completely to Ca(OH). An observed total initial weight (CaO + test tube) of 10.860 g goes eventually to 11.149 g. What is the weight of the test tube?
  79. Astronomy

    How do we image dark matter? (a) We see light from galaxies behind the bullet cluster that is bent (gravitationally lensed) due to the matter (regular and dark) in the bullet cluster. (b) We see light from the gas in the two bullet cluster galaxies and we observe that the gas ...
  80. math PLEASE HELP ME

    Mrs. Jones had some white paint and some green paint, and a bunch of wooden cubes. Her class decided to paint the cubes by making each face either solid white or green. Juan painted his cube with all 6 faces white - Julie painted her cube solid green. Hector painted 4 faces ...
  81. Math

    Mrs. Jones had some white paint and some green paint, and a bunch of wooden cubes. Her class decided to paint the cubes by making each face either solid white or green. Juan painted his cube with all 6 faces white - Julie painted her cube solid green. Hector painted 4 faces ...
  82. English

    After watching a documentary about the environment on TV, I decided to start my own project,"Project Green Kid." Today was my first day as a Green Kid...... ---------------------------------- Do we have to use "a Green Kid"? What about "a green kid"? Why do we have to ...
  83. Morales

    A black rectangular box is 8 inches longer than it is wide. A green rectangle box is 3 inches wider than the black box but it has the same length. The area of the green box is 39 square inches more than the area of the black box.
  84. Morales

    A black rectangular box is 8 inches longer than it is wide. A green rectangle box is 3 inches wider than the black box but it has the same length. The area of the green box is 39 square inches more than the area of the black box.
  85. chemistry

    Hi I am zahra rashedi. I am student on my maser projects in sharif universityy of technology.In my project, I must be obtained optimal condition for sterilization of baby powder with Ethylene oxide. There are two problems. When baby powder was sterilizated with EtO, some of ...
  86. Solubility/English

    Ok so I have this procedure to rewrite in past tense passive voice please help me out here I have alot ofthings to do with this lab...your help isgreatly appreciated. Thankyou! 1) Set up a hot-water both by placing th 250/400mL beaker, about two-thirds full of water, on the ...
  87. Chemistry

    What method of separation would you use for the following mixtures: acetone and water aluminum powder and ethyl alcohol. these were questions asked after a chapter of reading in my chem book. the separation techniques listed in the reading are filtration, distillation, and ...
  88. Biology

    Has anyone done this experiment before? I need help with the final results. What would happen when I place 2 mL of hydrogen peroxide into 5 test tube, add manganese dioxide powder to the first one, then add sand to the second one, liver to the third one, and ground liver to ...
  89. Physics

    The refractive index of a medium changes with the wavelength of incident light. Typically, the shorter the wavelength the larger the refractive index. Fused quartz has a refractive index of 1.47 for indigo light of 400 nm in wavelength, and a refractive index of 1.46 for green...
  90. Chemistry

    Three colorless solutions in test tubes, with no labels, are in a test tube rack on the lab bench. Lying beside the test tubes are three labels: potassium iodide, KI, silver nitrate, AgNO3, and sodium sulfide, Na2S. You are to place the labels on the test tubes using only the ...
  91. Chemistry-please help

    1) Metals that are above hydrogen in the reactivity series react with dilute hydrochloric acid to produce hydrogen gas. Lead is just above hydrogen in the reactivity series.I read a book that says no reaction occurs between lead & dilute acid. Why? Is it because the reaction ...
  92. Art... Color

    Hello, Does anyone know what colors( excluding black and gray) would communicate a solemn mood? I thought maybe different shades of yellow. For the reason blue and reds did not make sense nor did green, and violet is associated with royal, or majestic, so neither did that. ...
  93. physics

    4. Let's say you're driving in your car, approaching a red light on the Camp Hill Bypass. A black Porsche is stopped at the light in the right lane, but there's no-one in the left lane, so you pull into the left lane. You're traveling at 40 km/hr, and when you're 15 meters ...
  94. math

    A roulette wheel has 18 red slots and 18 black slots numbered alternately with the numbers 1 through 36. Two green slots are numbered 0 and 00. The winning number is determined by the slot into which a single marble rolls. Players are not allowed to bet on green. The house ...
  95. math

    A roulette wheel has 18 red slots and 18 black slots numbered alternaetly with the numbers 1 through 36. Two green slots are numbered 0 and 00. The winning number is determined by the slot into which a single marble rolls. Players are not allowed to bet on green. The house ...
  96. Math

    A jar contains 5 yellow marbles, 16 green marbles, and 8 black marbles. If one marble is selected at random, what is the probability that it is not green? 13 chances out of 16 (5/29*4/28)+(5/29*8/28)+(8/29*5/28)+(8/29*7/28)=39/203
  97. English

    Hello, Dr. Green. ------------------ In this expression, is Dr. Green a doctor who works at a hospital? Or is Dr. Green a professor in college?
  98. Statistical significance test

    I did a biology experiment where I need to analyze the statistical significance of betweeen a data set. My experiment consisted of measuring the effects in photosynthesis and cellular respiration by exposing solutions with leaf discs to different light wavelength. For the ...
  99. As physics

    Here are some questions to complete after you have determined the wavelength with a diffraction grating. (A laser was used) equation used: n x lambda=d x sintheta Question: What effect will the following have on the pattern produced? Explain your reasoning: 1.increasing ...
  100. Physics

    A photocell shows photoelectric effect when green light shines on it. Which of the following is correct if a green light is replaced by a blue light? Electron emission would get stopped. Electrons are emitted with more velocity. Electrons are emitted with less velocity. ...
  1. Pages:
  2. 1
  3. 2
  4. 3
  5. 4
  6. 5
  7. 6
  8. 7
  9. 8
  10. 9
  11. 10
  12. 11
  13. 12
  14. 13
  15. 14
  16. 15
  17. 16
  18. 17
  19. 18
  20. 19
  21. 20
  22. 21
  23. 22
  24. 23
  25. 24
  26. 25
  27. 26
  28. 27
  29. 28
  30. 29
  31. 30
  32. 31
  33. 32
  34. 33
  35. 34
  36. 35
  37. 36
  38. 37
  39. 38
  40. 39
  41. 40
  42. 41
  43. 42
  44. 43
  45. 44
  46. 45
  47. 46
  48. 47
  49. 48
  50. 49
  51. 50
  52. 51
  53. 52
  54. 53
  55. 54
  56. 55
  57. 56
  58. 57
  59. 58
  60. 59
  61. 60
  62. 61
  63. 62
  64. 63
  65. 64
  66. 65
  67. 66
  68. 67
  69. 68
  70. 69
  71. 70
  72. 71
  73. 72
  74. 73
  75. 74
  76. 75
  77. 76
  78. 77
  79. 78
  80. 79
  81. 80
  82. 81
  83. 82
  84. 83
  85. 84
  86. 85
  87. 86
  88. 87
  89. 88
  90. 89
  91. 90
  92. 91
  93. 92
  94. 93
  95. 94
  96. 95
  97. 96
  98. 97
  99. 98
  100. 99
  101. 100