Answer:
C. The half-life of C-14 is about 40,000 years.
Explanation:
The only false statement from the options is that the half-life of C-14 is 40,000yrs.
The half-life of an isotope is the time it takes for half of a radioactive material to decay to half of its original amount. C-14 has an half-life of 5730yrs. This implies that during every 5730yrs, C-14 will reduce to half of its initial amount.
- All living organisms contain both stable C-12 and the unstable isotope of C-14
- The lower the C-14 compared to the C-12 ratio in an organism, the older it is.
To increase the energy of the emitted electrons, the frequency of the incident light on the metal must be increased.
<h3>What is energy of emitted electron?</h3>
The maximum energy of an emitted electron is equal to the energy of a photon for frequency f (E = hf ), minus the energy required to eject an electron from the metal's surface, also known as work function.
Ee = E - W
<h3>Energy of the emitted electron</h3>
The energy of emitted electrons based on the research of Albert Einstein is given as;
E = hf
where;
- h is planck's constant
- f is frequency of incident light on the metal
Thus, to increase the energy of the emitted electrons, the frequency of the incident light on the metal must be increased.
Learn more about energy of electron here: brainly.com/question/11316046
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Nitrogen exists in the ocean in three redox states:
- In + 3 state as ammonium ion, NH4+
- In the 0 state as nitrogen gas
- In the +5 state as trioxonitrate (v) ion, NO3-
<h3>What are redox states?</h3>
The redox state of an element is the charge it appears to have in the free or combined state.
Nitrogen exists in the ocean in three redox states:
- In + 3 state as ammonium ion, NH4+
- In the 0 state as nitrogen gas
- In the +5 state as trioxonitrate (v) ion, NO3-
Therefore, the redox state of nitrogen varies in the ocean.
Learn more about redox state at: brainly.com/question/26263317
