Answer:
Element with the smallest radius is Carbon.
Explanation:
In a periodic table, atomic radius increases down the group due to addition of a new shell and decreases across the period from left to right due to increasing nuclear charge.
Due to addition of more electrons in same shell and increase of positive charge in nucleus increases attractive forces between electrons and nucleus hence decreasing size.
Carbon and Lithium are present in same period and hence Carbon has smaller size; Potassium and Bromine are present in same period and hence out of the two, Bromine has smaller size.
On comparing Carbon and Bromine, atomic radius increases down the group hence, Carbon has the smallest radius among the four given elements.
Answer:
c. Both i & ii
Explanation:
Moles do not change with temperature hence Mole fraction does not depends of temperature.
Molality is number of moles of solutes per kilogram of solvent. It has no relationship with temperature.
This means both of them do not change wit the change in temperature.
Correct option;
c. Both i & ii
Answer:
When an electric charge moves, heat is dissipated due to the drift velocity hence current is induced
Ice has the lowest energy; liquid water has “medium” energy; and water vapor has the highest energy.
Answer: -
4.25 mol of O₂ left as excess.
3.5 mol of NO₂ formed.
Explanation: -
Number of moles of NO taken = 3.5
Number of moles of O₂ taken = 6.0
The balanced chemical equation for this reaction is
2 NO+ O₂ → 2 NO₂
From the equation we can see that
2 mol of NO react with 1 mol of O₂
3.5 mol of NO react with 
x 3.5 mol NO
= 1.75 mol O₂
So Oxygen O₂ is in excess and NO is the limiting reagent.
Moles of O₂ left over = 6 - 1.75 =4.25 mol of O₂
From the balanced chemical equation we see
2 mol of NO gives 2 mol of NO₂
3.5 mol of NO gives
x 3.5 mol NO
= 3.5 mol of NO₂
