Answer:
B and D
Step-by-step explanation:
Answer:
Step-by-step explanation:
For a first order decay, fraction remaining = 0.5n where n = number of half lives elapsed.
fraction remaining = 55% = 0.55
0.55 = 0.5n
log 0.55 = n log 0.5
-0.2596 = -0.301 n
n = 0.8625 = # of half lives elapsed
0.8625 half lives x 2.5 billion years/half live = 2.16 billion years have elapsed = age of the rock
b) 0.15 = 0.5n
log 0.15 = n log 0.5
-0.824 = -0.301 n
n = 2.74 half lives
2.5 billion years/half life x 2.74 half lives = 6.85 billion years = age of rock
Answer:
Step-by-step explanation:
In order to find the slope, subtract -7 and -7, which is -7-(-7)=-7+7=0
Then subtract 7 and -2, which is 7-(-2) = 7+2=9
Divide 0 and 9 which equals 0
the slope is 0
Answer:
5:7
Step-by-step explanation:
140% of 30 is 42 so when i got that, i set up my proportion as 30:42 and then simplified
