The photo shows a roller coaster. Assume that the system is closed. Which roller coaster car has the least potential energy due to gravity? A. Car B
B. Car D
C. Car C
D. Car A

the energy to form plasma comes from heat or electricity in the atmosphere!

sunny~ ☺

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.  

explanation:

venn diagram is pictorial representation with of circles showing the relation between two finite sets or things. the intersection part of two circles conveys the relation present in between those sets or things.

here in the venn diagram of sand and salt two circles represent sand and salt. but the area falling under the intersection of these circle represents the mixture of sand and salt.

so, in a venn diagram the mixture will be placed in a middle that is in between the intersection of two circles.

the answer is true. hope it .