An element's period is it's row in the periodic tables.
A(t) = A(o)(½)^t/h
<span>A(t) /Ao = 0.5^t/h </span>
<span>Where A(t) = amount present, A(o) = initial amount, t = elapsed time, h = half-life </span>
<span>If 95% has been converted then At/Ao = 0.06 t½ = 15.0 h </span>
<span>log(0.06) = log(0.5)t/15 </span>
<span>15×log(0.05)/log(0.5) = t </span>
<span>t = 60.9 h </span>
List of covalent compounds
Binary molecular (covalent) compounds
compound systematic name
NO2 nitrogen dioxide
N2O3 dinitrogen trioxide
N2O4 dinitrogen tetroxide
N2O5 dinitrogen pentoxide
The density of helium is 10 ^-3g.cm^-3
One experimental property directly related to the strength of intermolecular forces is the boiling point of a substance.
In the liquid state, the intermolecular forces play a large role in the behavior of the substance. If the boiling point is low, this indicates weak forces such as Van der Waal's forces. On the other hand, a high boiling point indicates strong intermolecular forces such as hydrogen bonds.