a. They are both normally found as gases in the atmosphere. TRUE
That is correct, the oxygen and nitrogen are found in large quantities in the air around us.
b. They can be either liquids or gases. TRUE
Under certain temperatures any gas will transform into a liquid.
c.They turn from gas to liquid at the same temperature. FALSE
Oxygen it will pass into a liquid at -183 °C while nitrogen pass into a liquid at -195.8 °C.
d.They can be changed from gases to liquids by heating them. FALSE
The gases change to liquids by cooling them.
Explanation :
As we know that Mendeleev arranged the elements in horizontal rows and vertical columns of a table in order of their increasing relative atomic weights.
He placed the elements with similar nature in the same group.
According to the question, the atomic weight of iodine is less than the atomic weight of tellurium. So according to this, iodine should be placed before tellurium in Mendeleev's tables. But Mendeleev placed iodine after tellurium in his original periodic table.
However, iodine has similar chemical properties to chlorine and bromine. So, in order to make iodine queue up with chlorine and bromine in his periodic table, Mendeleev exchanged the positions of iodine and tellurium.
As we know that the positions of iodine and tellurium were reversed in Mendeleev's table because iodine has one naturally occurring isotope that is iodine-127 and tellurium isotopes are tellurium-128 and tellurium-130.
Due to high relative abundance of tellurium isotopes gives tellurium the greater relative atomic mass.
Description:
<span>"0.0400 mol of H2O2 decomposed into 0.0400 mol of H2O and 0.0200 mol of O2."
This means that a certain amount of H2O2 (0.0400 mol) decomposed or was broken down into two components, 0.04 mol of H2O and 0.02 mol of O2. To examine the system, we need a balanced equation:
H2O2 ---> H2O + 0.5O2
The final concentrations of the system indicates that the system is in equilibrium. </span>
The answer is transition metals.
