1) Californium-253 has a half-life of 18 days. Calculate how long it would take for the radioactive count in a sample to decrease from 4Bq to 0.25Bq (2 marks) 2) Carbon – 14 has a half-life of 5700 years. A count begins at 200 and many years later the count is done again and it is now 150. How many years later was that second count done? (2 marks)

3) The radioactive count of Rn-222 takes a 30.4 days to fall from 80000Bq to 312.5Bq. What is the half-life of Rn-222? (2 marks)

4) A man has just found what he believes to be a really old coin with his metal detector. Upon testing in the laboratory, the coin is found to have a C-14 reading of 1.6Bq. If the coin is believed to be 11400 years old and the half-life of C-14 is 5700 years, estimate the reading on the coin when it was new (3 marks)

5) The isotope Pu-238 has a half-life of 87.7 years and can be used to power generators. A generator contains 925g of Pu-238 and 1g of Pu-238 has a powe

your multimedia presentation should meet the following specifications: • it should be a minimum of four written paragraphs in length, which includes an introduction that previews the topic, incorporates facts, definitions, quotations, or other important information. • it should address all of the questions assigned in the webquest. • it should use vocabulary specific to the topic. • it should include a works cited page to document all sources. • it should reflect mastery of the basic rules of grammar, punctuation, and spelling. • it should use formatting, multimedia, and graphics to reinforce and extend the content. • it should include three multimedia elements and should use at least two of the following types of multimedia: 1. photographs 2. video clips 3. audio clips 4. maps 5. charts 6. graphs 7. works of art (such as original songs, sculptures, painting, performances) • it should be presented in one of the following formats: 1. word document 2. powerpoint presentation 3. prezi presentation can i have points idk the answer

"fire and ice" is one of robert frost's most popular poems. it was published in december 1920 in harper's magazine and in 1923 in his pulitzer prize−winning book new hampshire. it discusses the end of the world, likening the elemental force of fire with the emotion of desire, and ice with hate.

c. the power of desire is greater than the power of hate.

motion can be transfered from one object to another by having an objetct in motion push or hit it

where are the anwsers