Desert sand is very hot in the day and very cool at night. What does this indicate about its specific heat capacity?

Desert sand is very hot in the day and very cool at night. What does this indicate about its specific heat capacity?
Essay answers are limited to about 500 words (3800 characters maximum, including spaces).
16.40
On a cold day, why does a metal doorknob feel colder than the wooden door?
Essay answers are limited to about 500 words (3800 characters maximum, including spaces).
16.87
Your friend states that the average speed of all hydrogen and nitrogen molecules in a gas is the same. Do you agree or disagree, and why?
Essay answers are limited to about 500 words (3800 characters maximum, including spaces).
17.57
Why are icebergs often surrounded by fog?
Essay answers are limited to about 500 words (3800 characters maximum, including spaces).
17.75
When you boil potatoes, will your cooking time be reduced with vigorously boiling water instead of gently boiling water? (Directions for cooking spaghetti call for vigorously boiling water – not to lessen cooking time but to prevent something else. If you don’t know what it is, ask a cook.)
Essay answers are limited to about 500 words (3800 characters maximum, including spaces).
18.61
Could you cool a kitchen by leaving the refrigerator door open and closing the kitchen door and windows? Explain.
Essay answers are limited to about 500 words (3800 characters maximum, including spaces)