hellen

Most popular questions and responses by hellen
  1. chemistry

    An electron in a hydrogen atom makes a transition from an energy state of principal quantum numbers ni to n=2.If the photon emitted has a wavelentgh of 434nm what is the value of ni?

    asked on November 12, 2018
  2. Chemistry

    why is it important for company manufacturing vinegar to regularly check the molarity of its product?

    asked on May 17, 2010
  3. Botse botse high school

    Am a grade 10 learner n would like to know if i'll be able to become a social worker with the following subjects maths literacy , tourism , history and geography

    asked on June 30, 2015
  4. Chemistry

    The products for the following: CaCl2(aq) + K2CO3(aq) ¨ A. CaCO3(s) + 2KCl(aq) B. CaCO3(aq) + 2KCl(s) C. none of these D. no reaction

    asked on March 5, 2011
  5. Electronics

    Two resistors of 15ohms and 5ohms are connected in parallel.this parallel combination is connected in a series with a third resistor of 10ohms.the whole circuit is then connected across a 40 volts supply. 1.determine the resistance of the circuit. 2.the

    asked on March 14, 2013
  6. Easy math

    Eric has a 4 pound watermelon, 2 1/2 pounds of oranges, 3 pounds of apples, and a 1 1/2 pounds of grapes to make a fruit salad. How many pounds of fruit does he have in all? 1. 3 2. 10 1/2 3. 11 4. 15 1/2 Jeremy is baking a wedding cake and wants to be

    asked on January 20, 2015
  7. Physics

    a 4 kilogram ball moving at 8 meters per second to the right collides with a 1 kilogram ball at rest. After the collision, the 4 kilogram ball moves at 4.8 meters per second to the right. What is the velocity of the 1 kilogram ball?

    asked on March 27, 2012
  8. physics

    A 10kg box is attached to a 7kg box which rests on a 30 degrees incline the coeficient of kinetic friction is mk=0.1 between the box and surface find the rate of acceleration of the system

    asked on February 21, 2017
  9. Chemistry

    Aluminium react with oxygen to form aluminium oxide.how many grams of potassium chlorate V would be heated to produce enough oxygen to form 5.1grams of aluminium oxide

    asked on April 28, 2013
  10. chemistry

    Which reagents reagents to choose? The transformation shown below can be accomplished in TWO reaction steps. From the following list, select the two reagents (or sets of reagents) which would most effectively bring about this conversion. Reagents: 1. Conc

    asked on May 20, 2009
  11. MAth

    What should you say when you meet an angel

    asked on May 29, 2015
  12. physics

    Samantha is 1.21 m tall on her eleventh birthday and 1.32 m tall on her twelfth birthday. By what factor has her height increased?

    asked on January 17, 2015
  13. Chemistry

    The transformation shown below can be accomplished in TWO reaction steps. From the following list, select the two reagents (or sets of reagents) which would most effectively bring about this conversion. Reagents: 1. Conc H2SO4/heat 2. CN- 3. KMnO4 4. (i)

    asked on May 20, 2009
  14. science

    what does density mean in an easy way..! thank u

    asked on February 4, 2009
  15. WG

    i all ready did my work and i want to see if i got them right..... 1.what does a small blackened dot usually represent? Cities or towns. 2.which state contains the name of a country bordering united states? Canada. 3.what is the name given to the half of

    asked on January 22, 2009
  16. ADS

    hi for my english hw im suppose to find three ads for the same product one from 2006 one from 1980s-2000 and one from before the 1980s and showing how the ad has developed throughout the years, but the ad has to be provacative like the selling of a car

    asked on October 13, 2006
  17. Physics

    A satellite orbits the moon at height of 2000m.assuming it to gravitational pull of the moon,find the speed and time it takes for one orbit,given that mass of moon is 7.34 * 10 to power 22 kg and radius is 1.738 * 10 to power 6m.(g = 6.6 * 10 to power

    asked on October 16, 2016
  18. life orientation

    identifie 5 ways in which the environment /human factor impact on the community

    asked on July 11, 2013
  19. WG

    i all ready did my work and i want to see if i got them right..... 1.what does a small blackened dot usually represent?

    asked on January 22, 2009
  20. Electronics

    Rseries=R1+R2 =15ohms+10ohms =25ohms

    asked on March 14, 2013
  21. math

    31m^2n/41 x 21/mn x 2n^2/3m

    asked on December 1, 2008
  1. algebra

    I dont know

    posted on December 6, 2017
  2. 5th grade

    Wbvsbd

    posted on February 19, 2016
  3. Botse botse high school

    Thank u m.s sue you're the best

    posted on June 30, 2015
  4. Botse botse high school

    Thank u ms sue . Wat are other careers i can take i hear that with the subjects lyk mine its hard to find a good stable job

    posted on June 30, 2015
  5. math

    What should you say when you meet an angel

    posted on May 29, 2015
  6. Easy math

    1. 11 ? 2. 7/9 ?

    posted on January 20, 2015
  7. Easy math

    How I'm suppose to solve them? Like should I subtract, add, multiply

    posted on January 20, 2015
  8. Social Civics

    for the first its A

    posted on April 6, 2011
  9. physics

    An essay of how gravitational acceleration is used to benefit mankind and the environment.how can rural people also benefit from the use of gravitational acceleration?

    posted on February 15, 2011
  10. science

    thx i got a c that's good anuff for me

    posted on March 11, 2010
  11. WG

    2.which state contains the name of a country bordering united states? is it New mexico i checked again.!!!

    posted on January 22, 2009