To answer this question, you need to understand the naming of meter unit system. The unit pm stands for pico meter which was 1/1000 of nanometer. Then, the calculation would be:
Number of atom= container length / atom diameter
Number of atom = 25 nm x (1000pm/nm) / 144pm= 173.6 atom
There should be a sufficient amount of the selected isotope in the rock.
The half-life of the isotope must be long enough to capture the age of the rock.
Explanation:
Sully must consider two main aspect before selecting her choice isotope for dating.
There must be sufficient amount of the selected isotope in the rock.
The half - life of the isotope must be long enough to capture the age of the rock.
- Radiometric dating gives a rock an absolute numerical age.
- The half-life of an isotope is time take for half of a radioactive element to decay.
- If the half-life of an isotope is very short, all the parent nuclide would have turned to daughter nuclides.
- Also, we must have sufficient amount of both the daughter and parent isotope in the selected rock.
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Answer : 
Explanation : In the molecule of the hydrogen bonding forces tend to resist any phase transition form liquid state to gaseous phase, and these hydrogen bonding forces are greater usually when the hydrogen is bound to an electronegative atom like chlorine, fluorine,oxygen,etc. This then lowers the viscosity of the compound.
Answer: The ions which are not spectator ions are 
and 
Explanation:
Spectator ions are defined as the ions which does not get involved in a chemical equation or they are ions which are found on both the sides of the chemical reaction present in ionic form.
The given chemical equation is:
The ions which are present on both the sides of the equation are 
and 
and are spectator ions.
Thus the net ionic equation is:
Hence, the correct answer is and
