Give a reason for the following: We can get the smell of perfume sitting several meters away

Give a reason for the following:

It is easy and faster to sip tea from a flat plate rather than a glass. 

Give a reason for the following:

Wearing cotton clothes is more comfortable in summer.

Give a reason for the following:

At 273 K ice is more effective in cooling than water at the same temperature.

Give a reason for the following:

Steam produces more severe burns than boiling water.