Two electrons are placed; one at north pole and other at south pole of earth. Find the force between them. Given diameter of earth= 12800 km.

100,104 results, page 84
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

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

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

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

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

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