If you're dealing with gases, some of them could escape the container. Or, if you're dealing with liquids, there could be some outside factors playing in. In general, you need a closed system to observe a reaction accurately.
This is the only option that correctly describe characterisitics of noble gases.
All noble gases have a unique atomic fingerprint.
All noble gases have valence shells with 8 electrons but Heilum has only 2 valence electrons.
And all noble gases do not easily react with other elements as they have their outermost shell completly filled so they are highly stable.
All noble gases emits different colored light when electrified.
Considering a reaction:
A → B
The rate equation may be described as:
r = -k[A]ⁿ
Taking the natural log,
ln(r) = -nln([A]) + ln(k)
Therefore, the only time the graph of ln[A] vs time will be a straight line is when the order of the reaction is 0, meaning the reaction is independent of reactant concentration.
The first basic metals on the periodic table are alkali metals.
