I'm assuming that you are asking a general question because you did not include an example.
The limiting reagent is the item in the reactants (reagents) that will run out first. This is because it limits what the reaction can produce, essentially causing the leftover elements/compounds to just sit there.
Answer: Option (d) is the correct answer.
Explanation:
In winter's, temperature of atmosphere is low and due to this molecules of air present in the tire come closer to each other as they gain potential energy and loses kinetic energy.
Hence, air pressure decreases and there is need to fill more air in the tire.
Whereas is summer's, temperature is high so, molecules of air inside the tire gain kinetic energy and move rapidly from one place to another due to number of collisions. So, air pressure increases and there is no need to fill more air inside the tire.
Thus, we can conclude that the temperature is lower, so the air inside the tires contracts.
Answer : The approximate relation Celsius = 1/2 Fahrenheit is a better approximation at higher temperatures
Explanation :
The formula for Celsius to Fahrenheit conversion is

At lower temperature the value that needs to be subtracted (32) is large enough as a result the approximation "celsius = 1/2 fahrenheit " does not seem valid.
For example, 50 F is 10°C.

This is almost 1/5 of Fahrenheit temperature.
But at higher temperatures , the value becomes insignificant and also the ratio 5/9 tend to be equal to 0.5.
For example, 2000 F is 1093°C

This is almost half of Fahrenheit temperature.
Therefore , the approximate relation Celsius = 1/2 Fahrenheit is a better approximation at higher temperatures
The difference between the wattage is 60-18=42W. The saving in energy over 10 hrs is 10×42=420 watt-hours=0.42kWh
Fluorine! It's highly reactive, since it has 7 electrons and wants an extra electron to fill its valence shell.