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

Wichita mourning david matherne pipe organs—dusty and tarnished— bellowed the ancient song, as movers carried the pews for one last time. frozen branches—heavy with ice arms— 5 couldn’t perform their dance, as workmen shuffled inside the worn-out floors. sally richards—broken and mourning— watched while her father left, 10 as painters brought in their cans for the first time. stained-glass windows—buckled and broken— surveyed commotion’s cause as commerce won in the end 15 yet one more time. reverend richards—feeble and finished— cried as his exit was lost on christians who worshiped the dime; a change of the times. 20 which of these best summarizes the author's style in this poem? a) each of the five stanzas contains internal rhyme and consistent rhythm. b) each of the five stanzas contains an end rhyme describing a different character. c) each of the five stanzas contains assonance followed by a dash, then a description of the old church. d) each of the five stanzas introduces a character followed by a dash, then a description of that character. 3) in the first line of each stanza, the author follows the pattern of a noun followed by a pair of adjectives. what is the purpose of this pattern? a) the author hopes to create a peaceful feeling for the readers. b) the object and its adjectives are used to create a sense of progress. c) the author uses the pattern to create vivid pictures in the reader's mind. d) the author uses the pattern of man and nature to show the impact of this event.

In virginia woolf's essay "a room of one's own," she creates a fictional sister of william shakespeare, whom she names "judith." what challenges does woolf claim this character would have experienced in her lifetime? why does woolf believe that elizabethan women did not write?

Question 9 (5 points) dother, the evil, hated everything. dian, the violent, was a walking nightmare, leaving a bevy of victims wherever he traveled. what does the underlined word mean in the above quote from the legend of carman? a)a small number b)very few c)a minuscule amount d)a large number