1. science

    I am studying science at GCSE. I a working through a revision book and have come across a question which i am unsure of the answer. The question is, "state the number of different elements present in C6H5CO2Na." The answer i have is 14 but still i am

    asked by sam on March 19, 2007
  2. History

    What Demographic Transition Model stage is Belize, Cuba, GReece, Swaziland, Switzerland, Vietnam, South Korea, Niger, Uruguay,and Haiti in? Is there a website to get accurate answers? I think Belize is stage 2, Cuba is stage 3, Greece is 4, Swaziland 3,

    asked by Geo on October 27, 2015
  3. Chem

    Hello What is the wavelength (in nm) of the line in the spectrum of the hydrogen atom that arises from the transition of the electron from the orbital with n =5 to the orbital with n = 2? Note, the line corresponds to the energy of the photon that is

    asked by Anonymous on October 26, 2012
  4. math

    Sam and markus are standing on level ground 100m apart. A large tree is due north of markus and on a bearing of 65degrees from sam. The top of the tree appears at an angle of elevation of 25degrees to sam and 15degrees to markus. Find the height of the

    asked by putri on November 12, 2010
  5. chemistry

    what is the binding energy of an electron in a photosensitive metal (in kj/mol) if the minimum frequency of light that can eject electrons from the metal is 6.3 x 20^14 Hz?

    asked by jj on November 7, 2011
  6. Science

    A 6.0 volt battery is hooked up to a light bulb, whose resistance is 3.1 ohms. How many electrons would leave the battery per second? (Hint: 1 electron = 1.6E-19 C)

    asked by David on September 28, 2009
  7. chemistry

    Please explain this to me 2I- --> I2 + 2e Cr2O72- ==> Cr3+ 6e + 14H + Cr2O72- ==> 2Cr3+ + 7H20 I don't understand how the left side gets 6 electrons.

    asked by Monique on November 21, 2011
  8. Organic Chemistry

    What is the mechanism of action between between benzoic acid (C6H5COOH) and sodium bicarbonate (NaHCO3)? I need to know where the electrons go in the acid-base reaction.

    asked by BOB on October 12, 2011
  9. Physics E&M

    Three electrons form an equilateral triangle 1.00 nm on each side. A proton is at the center of the triangle.What is the potential energy of this group of charges?

    asked by Spencer on February 18, 2008
  10. Chemistry

    Examine the redox reaction. As2O3(s) + Cl2(g) + H2O(l) → H3AsO4(aq) + HCl(aq) How many electrons are lost by each As atom during the reaction? A)4 B)3 C)2 D)1

    asked by Spencer on June 22, 2018
  11. science

    i have a work sheet to do it gives me the atomic number and the mass number of elements i have to fill in the missing electrons protons neutrons

    asked by austin on October 4, 2012
  12. physics

    Problem 22.2 2 *10^13 electrons flow through a transistor in 1.0ms . Part A - What is the current through the transistor? Express your answer using two significant figures. in mA

    asked by Paige on September 25, 2011
  13. Pre-AP Science

    an atom consists of 10 neutrons ,10 electrons,and 9 protons. The atom has gained an electron resulting in a charge of -1. What is its mass number?

    asked by Christina on February 5, 2013
  14. Physics

    At what distance from a carbon nucleus is the electric potential 1.8 V? Carbon atoms have 6 electrons in the atomic shell ...im very confused with this question, please help!

    asked by Lauren on March 1, 2010
  15. Chemistry

    A metal foil has a threshold frequency of 5.45× 1014 Hz. Which of the colors of visible light have enough energy to eject electrons from this metal.

    asked by Jake on October 10, 2013
  16. Chemistry

    What is the electron configuration called that has 18 electrons in the outer energy level and all of the orbitals filled? Noble gas configuration

    asked by Bryan on November 16, 2006
  17. Physics

    In a computer monitor, an electron beam with a current of 4x10^-6 A is directed at the screen. How many electrons are transferred to the monitor in 2 minutes.

    asked by Yvonne on May 11, 2012
  18. Physics

    When two identical ions are separated by a distance of 5.9 multiplied by 10-10 m, the electrostatic force each exerts on the other is 6.0 multiplied by 10-9 N. How many electrons are missing from each ion?

    asked by Alex on June 28, 2012
  19. Marianne

    Fill in the blank: The electrons follow a ________ path when they are deflected in a magnetic field due to the magnetic force.

    asked by Physics on March 13, 2015
  20. physics

    Calculate the net charge on a substance consisting of a combination of 8.9 × 10 13 protons and 2.6×10 13 electrons. The elemental charge is 1.6 × 10 −19 C. Answer in units of C

    asked by sara on November 18, 2012
  21. physics

    at what distance would repulisve force between two electrons have a magnitude of 2.00 n between two protons ? 2=kq1q2/r^2 r^2 = 9.0 x10^9 x (1.6 x 10^-19)^2 So, what is the R, on my answer from, this is 1.07 x10^-14m, however, I cannot get this, can you

    asked by yan on February 21, 2013
  22. SCIENCE HELP ASAP

    1. in an atom, electrons_____ 2. dot diagrams are used to represent_______ 3. the maximum number of electrons in the second energy level of an atom is________

    asked by schweppes on February 28, 2017
  23. physics

    two identical copper spheres are separated by 1m in vacuum. how many electrons would have to be removed from one sphere and added to other sphere so that they attract each other with force of 0.9N

    asked by divy on June 3, 2014
  24. Write the shorthand notation

    Write the shorthand notation and the orbital diagram electron configuration representation for each of the following elements and indicate the orbital(s) which contain valence electrons: (a) N, (b) K, (c) Cu, (d) Al.

    asked by gabyj on August 17, 2010
  25. physical science

    A kg ball of lead rests next to a 10 kg rock. which statement below is true:a:the lead ball and rock have the same amount of inertia,b:if the lead ball and the rock fell from the same height in a vacuum, the rock would hit the ground first because it is

    asked by ellen on January 29, 2011
  26. physics

    A satellite orbits a planet at a distance of 3.80 108 m. Assume that this distance is between the centers of the planet and the satellite and that the mass of the planet is 3.90 1024 kg. Find the period for the moon's motion around the earth. Express the

    asked by Blake on February 17, 2012
  27. Physics

    Relative to the ground, a car has a velocity of 14.8 m/s, directed due north. Relative to this car, a truck has a velocity of 24.0 m/s, directed 52.0° north of east. What is the magnitude of the truck's velocity relative to the ground?

    asked by Erin on January 26, 2012
  28. Trig/Physics

    Joe walks 5 miles in the direction degrees North of East, and then 10 miles in the direction 20 degrees West of North. (a) How far is Joe from his starting position? (b) In what direction is Joe from his starting position?

    asked by Nycw on July 19, 2012
  29. physics

    Relative to the ground, a car has a velocity of 14.4 m/s, directed due north. Relative to this car, a truck has a velocity of 24.8 m/s, directed 52.0° north of east. What is the magnitude of the truck's velocity relative to the ground?

    asked by randy on October 6, 2011
  30. Astrophysics

    The Earth formed at a redshift of z∼0.53. That means that when our world was young, the universe was quite a bit smaller than it is today. The nearest galaxies to our own are around 10 kpc (kilo-parsecs) in size, lie at a distance of around 1 Mpc from us

    asked by Anonymous on April 12, 2014
  31. english fixed-3

    here's what i did for number 4. The world is deserting because we are taking water for granted. If people continue to waste water, the earth’s structure will change and it will be the main cause of earthquake and potentially a tsunami. and for number 5.

    asked by ESLstudent on February 28, 2012
  32. Physics

    At what rate will a pendulum clock run on the Moon, where the acceleration due to gravity is 1.63 m/s2 , if it keeps time accurately on Earth? That is, find the time (in hours) it takes the clock’s hour hand to make one revolution on the Moon. provide

    asked by Ellie on February 4, 2013
  33. Language

    People have been making maps for hundreds of years. Christopher Columbus used maps when he sailed to the "New World." At that time, most people thought Earth was flat, and all of the maps they used were flat, too. Of course, Columbus's maps were not

    asked by Estephania on January 13, 2016
  34. Earth

    1. If the Earth were the size of B-B (with a radius of about 0.2 centimete), how big would the Sun be? How big would the Milky Way be? 2. Imagine building a model of the Solar System on your campus. Work out the diameter and spacings of the planets in

    asked by Sunny on April 3, 2007
  35. Calc

    Recent studies indicate that the average surface temp. of the earth has been rising steadily. Some scientists have modeled the temp. by the linear function T= 0.02t + 8.50, where T is temp. in degrees Celsius and t represents years since 1900. What do the

    asked by Chelsea on September 20, 2010
  36. Physics

    1) Find the magnitude of the gravitational force a 68.6 kg person would experience while standing on the surface of Earth with a mass of 5.98 × 10 24 kg and a radius of 6.37 × 10 6 m. The universal gravitational constant is 6.673 × 10 −11 N · m2 /kg

    asked by Jocelyn on January 30, 2013
  37. Social Studies

    1. How has South Carolina changed politically since the 1970s? (1 point) ~County governments were eliminated. ~Race has become the most important political issue.***** ~The Democratic Party has gained more power in the state. ~The Republican Party has

    asked by Please Check My Answers on May 31, 2016
  38. chem

    What is the wavelength (in nm) of the line in the spectrum of the hydrogen atom that arises from the transition of the electron from the orbital with n =5 to the orbital with n = 2? Note, the line corresponds to the energy of the photon that is emitted in

    asked by Anonymous on October 26, 2012
  39. physics

    It has been suggested, and not facetiously, that life might have originated on Mars and been carried to Earth when a meteor hit Mars and blasted pieces of rock (perhaps containing primitive life) free of the surface. Astronomers know that many Martian

    asked by Anonymous on September 14, 2014
  40. Science

    Does the Earth and moon have large molten core or only 1 of them does? I think the Earth only has large molten core

    asked by Jaycee on November 29, 2011
  41. history

    what was napolean like in the north america?

    asked by Emma on October 18, 2010
  42. 6th grade

    most of the islands in north belong to

    asked by me on November 24, 2009
  43. physics

    What is mean by 28degree east of north

    asked by Anonymous on December 14, 2016
  44. science

    where does energy come from in north carolina

    asked by shadow on November 1, 2017
  45. Social Studies

    How many states are in North America?

    asked by Will on April 30, 2008
  46. physics

    750km towards North West?

    asked by sana on May 20, 2015
  47. Geology

    Can someone please look this over and let me know if I described the Plate Tectonic Theory? Thanks. Write a 200-300-word summary about two historical figures and the process of mantle convection and plate movement. Two historical figures that contributed

    asked by A.W. on April 8, 2009
  48. Physics

    A 7410-kg satellite has an elliptical orbit, as in the figure. The point on the orbit that is farthest from the earth is called the apogee and is at the far right side of the drawing. The point on the orbit that is closest to the earth is called the

    asked by Anonymous on November 13, 2012
  49. Physics

    A 7410-kg satellite has an elliptical orbit, as in the figure. The point on the orbit that is farthest from the earth is called the apogee and is at the far right side of the drawing. The point on the orbit that is closest to the earth is called the

    asked by Donald on November 11, 2012
  50. geology

    How old are the oldest meteorites yet studied and what is the minimum age of Earth since Earth is at least as old as the meteorites. We know the oldest meteorites contain equal amounts of uranium 238 and lead 206. Uranium 238 has a half life of 4.5 billion

    asked by m on November 21, 2010
  51. history

    Please verify: the workers that were generally better off in America than Europe before 1860 would have been the skilled workers? The most important iron manufacturing center in the South was the Atlanta Iron Foundry? Utopian societies emerged in the

    asked by lm on November 30, 2009
  52. science

    1. Scientists hypothesize that the sun formed ____. (1 point) less than a billion years ago from a cloud of gas and dust less than a million years ago from a chunk of Jupiter 2. Two of the inner planets are ____. (1 point) Venus and Saturn Mars and Venus

    asked by jessie on February 12, 2013
  53. Geometry

    Eratosthenes knew that in Aswan the sun was directly overhead at noon on the summer solstice. At the same time, he measured the angle of the sun to a vertical line in Alexandria. He found this angle to be one(1/50) fiftieth of a circle a. What was

    asked by James on August 29, 2018
  54. 7th grade Science help

    1. _______ is energy that flows from an object with a higher temperature to an object with a lower temperature. (1 point) Heat Radiation Potential Chemical 2. The transfer of energy that occurs when molecules bump into one another is called _____. (1

    asked by Delilah on September 26, 2012
  55. physics

    An aircraft is flying at the speed of 354km/hr relative to the air is observed from the ground to have a velocity of 300km/hr in the north east direction. The wind is blowing from east. Find the speed of the wind and the direction to which the aircraft is

    asked by george on August 10, 2012
  56. math

    Two helicopters leave Springfield, IL at the same time. One travles north at 27 miles per hour and the other travels west at 120 miles per hour. How far apart are they after 3 hrs? (Hint: Use d=rt to find the distance traveled by each helicopter.) I know

    asked by Rmz on January 28, 2010
  57. Physics

    Two movers push horizontally on a refrigerator. One pushes due north with a force of 150 N and the other pushes due east with a force of 200 N. (a) Find the direction and magnitude of the resultant force on the refrigerator. (b)Show that the result of the

    asked by Tezara on January 23, 2011
  58. history

    What would be a good thesis statement for my intro paragraph? Effect and Evolution of African Americans in Minnesota Intro The first Great Migration occurred after the Civil War and after the 13th amendment was passed. With the passing of the 13th

    asked by Sasha on November 11, 2009
  59. Maths

    A straight river flows at a speed of 20km/h. A boater starts at the south shore and heads in ths direction of 70degrees from the shore. The boat has a speed of 20km/h in still water. Find the true speed and direction of the boat.

    asked by Anonymous on February 26, 2013
  60. Pre calculus, vectors

    A straight river flows at a speed of 20km/h. A boater starts at the south shore and heads in ths direction of 70degrees from the shore. The boat has a speed of 20km/h in still water. Find the true speed and direction of the boat.

    asked by Halala on February 26, 2013
  61. Environmental Problems

    Where in the US and Canada is deforestation, air pollution, water pollution, and climate change happening? San Francisco Aereas near all population centers would be the most acute, as you get further North the polution is less and, the deforestation is

    asked by Amanda on November 15, 2006
  62. History

    4. South Carolina responded to the Intolerable Acts by __________. (1 point) holding small “tea parties” in Charles Town and Georgetown sending representatives to the First Continental Congress drafting a state constitution and setting up a new

    asked by Anonymous on October 28, 2014
  63. physics

    A cyclist starts from point X and rides 3 km due west to point Y. At Y he changes direction and rides 5km north-west to point Z. (a) hw far is he from the starting point, correct to the nearest km? Find the bearing of the Z frm X to the nearest degree?

    asked by Anonymous on March 11, 2012
  64. trig

    two trains leave Kansas City at the same time. Train A is traveling due north at 55 mph, train B is traveling west at the rate of 65 mph. Find the distance between the two trains two hours later and the bearing of train B from train A.

    asked by Anonymous on October 16, 2012
  65. physics

    Calculate the tidal force experienced by Io. How does it compare to the tidal force experienced by the Moon due to the Earth? What would the Earth-Moon distance (i.e., distance between their centres) need to be in order for the Moon to experience similar

    asked by roach on November 20, 2011
  66. astronomy

    Calculate the tidal force experienced by Io. How does it compare to the tidal force experienced by the Moon due to the Earth? What would the Earth-Moon distance (i.e., distance between their centres) need to be in order for the Moon to experience similar

    asked by roach on November 20, 2011
  67. Physics

    Calculate the net charge on a substance con- sisting of a combination of 7.2 × 1013 protons and 4.8 × 1013 electrons. Answer in units of C

    asked by Amanda on February 28, 2012
  68. science

    6.023*x10^21 electrons are present n a given amount of ammonium (NH3).How much amount of hydrogen is required to produce the sample of ammonia

    asked by sandhya on October 4, 2016
  69. Math

    The avearage velocity of the electrons in a conductor carrying a current of 65.5 ampere is 0.0153 inches per second. What is the cross sectional area of the conductor?

    asked by Anonymous on September 18, 2018
  70. E& M physics

    Three electrons form an equilateral triangle 0.600 nm on each side. A proton is at the center of the triangle. What is the potential energy of this group of charges?

    asked by Master Blaster on October 2, 2015
  71. Chem

    Which defines what element the atom is? a. protons b. neutrons or d. electrons. I think it might be neutrons, but can you verify this? AND Would the property "reacts in water" be physical or chemical? Thanks.

    asked by Mora on June 9, 2009
  72. Science

    4. 3 elements are listed by atomic number, #19, 20, and 21. Which property do all of these elements have in common? They are all brittle. They all have 4 valence electrons. They are all malleable. ***** They shatter easily.

    asked by ThatGirl on January 31, 2018
  73. physics

    2.4 ampere current is flowing in a wire .how many electrons pass a given point in the wire in one second if the charge on an electron is 1.6x10 power -19 couloms.

    asked by komal yaseen on December 31, 2014
  74. Physics

    Electrons are accelerated to reach a kinetic energy of 250 eV (= 4.0 x 10-17 J). If the acceleration is done in a distance of 0.20 m, what is the magnitude of the electric field causing the acceleration?

    asked by Lauren on March 12, 2013
  75. Chemistry-Explanation Please

    How many valence electrons are in the following? (Remember to add an electron for each negative charge or to subtract one for each positive charge). ICl2− ONF CH4

    asked by Yaw on November 20, 2012
  76. physics

    Calculate the net charge on a substance con- sisting of a combination of 6.5 × 1013 protons and 2.0 × 1013 electrons. Answer in units of C.

    asked by Anonymous on February 9, 2010
  77. Chemistry

    A potassium metal has a work function F = 4.41 x 10-19 J. Calculate the velocity of electrons emitted by exposing the metal to radiation of wavelength 300 nm.

    asked by Kevin on May 1, 2018
  78. chem

    CF4 how would you determine the molecular shape using vsepr? i got that it has 32 electrons and four bonds. im stuck on how to get the non bonding domains and shape and bond angle! thanks!

    asked by skye on March 13, 2012
  79. Physics

    Calculate the net charge on a substance con- sisting of a combination of 3.5 × 1013 protons and 6.3 × 1013 electrons. Answer in units of C.

    asked by lucky on April 8, 2011
  80. Chemistry

    How many electrons will each element gain in forming an ion? a. Nitrogen ______ b. Oxygen ________ c. Sulfur _______ d. bromine _______

    asked by Greg on October 10, 2012
  81. Chemistry (Check)

    Completion is these correct. I can't figure out 5,7,8,9.. 1)equally 2)Non-polar 3)un equally 4)polar bond 5) 6)clipore interactions 7) 8) 9) When atoms are joined by a covalent bond, the bonding electrons are shared ___1____, and the bond is ___2___. When

    asked by Bryan on January 3, 2007
  82. Chemistry

    The number of protons in a cation must always be ________ the number of electrons.

    asked by Dominick on December 9, 2015
  83. ochemistry

    How many pi-electrons are in the thiazoline ring of thiamine hydrochloride? of thiamine?

    asked by lori on July 5, 2011
  84. Ap CHem

    For how many electrons in Sr. Does A)n=4; l=1 B)n=3;l=2;ml=1 C)n=1;l=1;ml=0 You must know the variations possible. n = 1, 2, 3, ...... l = 0, 1, 2, etc up to n-1. ml=-l to +l (this is -ell to +ell) ms = +/- 1/2 Start with n = 1 and work your way up.

    asked by Susie on October 30, 2006
  85. Physics

    A metal sphere has a charge of -6 µC. How many excess electrons are there on the sphere?

    asked by anonymous on January 31, 2013
  86. physics

    A metal sphere has a charge of -6 µC. How many excess electrons are there on the sphere?

    asked by Talia on August 20, 2013
  87. Science

    What is the max number of electrons in an atom that can have the quantum number: n=2, ms= -1/2

    asked by Kael on August 25, 2018
  88. earth science

    An element's atomic number is 52. How many electrons would an atom of this element have?

    asked by laura on May 4, 2018
  89. hcc

    how do the masses iof electrons compare with the masses of protons?

    asked by jenna on October 29, 2008
  90. physics

    A metal sphere has a charge of -6 µC. How many excess electrons are there on the sphere?

    asked by Tam on January 1, 2016
  91. Chemistry

    What are the repulsion of protons from one antoher and the repulsion of electrons from one another responsible for?

    asked by Lola on January 11, 2011
  92. science

    An element's atomic number is 52. How many electrons would an atom of this element have?

    asked by jessica on May 4, 2018
  93. Math 115 CH 8

    Compare the population per square mile in Asia to the population per square mile in North America for the year 2000. North America : land area 9,400 (1,000 mi squared) population 305,000,000 Do I divide 305,000,000 by 9,400,000? and do the same for Asia?

    asked by Debbie on December 8, 2008
  94. abac

    The speed of an object and the direction in which it moves constitute a vector quantity known as the velocity. An ostrich is running at a speed of 19.5 m/s in a direction of 65° north of west. (a) What is the magnitude of the ostrich's velocity component

    asked by heather on August 30, 2010
  95. Algebra ii

    City B is due north of city A. City A has a latitude of 14.6 degrees N, and city B has a latitude of 47.2 degrees N. find the distance in kilometers between the cities.

    asked by Arielle on November 3, 2011
  96. physics

    An unsuspecting bird is coasting along in an easterly direction at 4.00 mph when a strong wind from the south imparts a constant acceleration of 0.300 m/s2. If the acceleration from the wind lasts for 2.70 s, find the magnitude, r, and direction, θ, of

    asked by Jordan on September 8, 2015
  97. Math

    A year on Mars is 686 Earth Days. (1) Which is longer, a year on Mars or a year on Earth? (2)By how many weeks is it longer? Submit two answers. Please explain how you got the answers. My 1st answer was Mars the 2nd answer I 82 1/2 weeks. Please help

    asked by Nakia on September 5, 2012
  98. global

    why could it be said that the historic period is only a minute in comparison ti the 24 hours of the day? The historic period began about 5,000 years ago when writing was first developed in Mesopotamia (now Iraq). Modern man has existed for at least 100,000

    asked by Victoria on July 23, 2007
  99. Social Studies 7R (Letter)

    Please check this letter if it's good and if there any grammar mistakes. My most exalted Monarch - Your Majesty Queen Isabella, I am writing this letter most humbly for you to consider my request for three small ships and a crew so that I may sail west and

    asked by Laruen on November 18, 2011
  100. Physics

    The weight of an astronaut plus his space suit on the Moon is only 270 N. A. How much do they weigh on Earth, in Newtons, assuming the acceleration due to gravity on the moon is 1.67m/s^2= 1584is this right? B. What is the mass of the astronaut and his

    asked by Flo on September 2, 2015