The atomic number is the number of protons in the nucleus of an atom. The number of protons define the identity of an element (i.e., an element with 6 protons is a carbon
So I believe it’s 6 hope this helps if not reply back
A). m/s ... meters per second.
That's a speed.
b). m/s² ... (meters per second) per second.
Acceleration.
c). m²/s ... square meters per second.
Rate of change of area.
Meaningless unit, unless you happen to be
a painter of houses or a mower of lawns.
d). kg-m/s² ... (mass) x (an acceleration).
This is a unit of force.
In fact, it's the definition of "newton".
Answer:
8. 2.75·10^-4 s^-1
9. No, too much of the carbon-14 would have decayed for radiation to be detected.
Explanation:
8. The half-life of 42 minutes is 2520 seconds, so you have ...
1/2 = e^(-λt) = e^(-(2520 s)λ)
ln(1/2) = -(2520 s)λ
-ln(1/2)/(2520 s) = λ ≈ 2.75×10^-4 s^-1
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9. Reference material on carbon-14 dating suggests the method is not useful for time periods greater than about 50,000 years. The half-life of C-14 is about 5730 years, so at 65 million years, about ...
6.5·10^7/5.73·10^3 ≈ 11344
half-lives will have passed. Whatever carbon 14 may have existed at the time will have decayed completely to nothing after that many half-lives.
Do you mean in general or in a piece of paper?
