Answer : C
Because $6.65 multiplied by 4 hours equals $26.60
Answer:
a) a0 was 46.2 grams
b) It will take 259 years
c) The fossil is 1845 years old
Explanation:
<em>An unknown radioactive substance has a half-life of 3.20hours . If 46.2g of the substance is currently present, what mass A0 was present 8.00 hours ago?</em>
A = A0 * (1/2)^(t/h)
⇒ with A = the final amount = 46.2 grams
⇒ A0 = the original amount
⇒ t = time = 8 hours
⇒ h = half-life time = 3.2 hours
46.2 = Ao*(1/2)^(8/3.2)
Ao = 261.35 grams
<em>Americium-241 is used in some smoke detectors. It is an alpha emitter with a half-life of 432 years. How long will it take in years for 34.0% of an Am-241 sample to decay?</em>
t = (ln(0.66))-0.693) * 432 = 259 years
It will take 259 years
<em>A fossil was analyzed and determined to have a carbon-14 level that is 80% that of living organisms. The half-life of C-14 is 5730 years. How old is the fossil?</em>
<em />
t = (ln(0.80))-0.693) * 5730 = 1845
The fossil is 1845 years old
<h2>
Answer:</h2>
We will need to know Avogadro's number and the molar mass of sucrose for this problem to do dimensional analysis.
- Avogadro's number: 6.022 × 10²³ molecules
- Molar mass of sucrose: 342.2965 g/mol
250g × 
× 
= 4.398 molecules
There are <em>4.398 sucrose molecules </em>in 250 grams of sucrose.
B. They are the same force. Each body acts on the other. The moon and the earth, and the apple and the earth.
I believe that the answer is molecule
