Which of the following expands to fill the container it is in but can be compressed to a smaller volume when pressure is applied?
a. solid iron
b. liquid bromine
c. neon gas
d. sugar crystals

C. neon gas

Explanation:  There are three states of matter:

A. Solid iron: The molecules in solid are very tightly packed as inter molecular forces are very high. There is very less space between the particles and thus the molecules can not be compressed. They have fixed shape and volume.

B. liquid bromine: The molecules in liquid are less tightly packed as inter molecular forces are not very high. There is less space between the particles and thus the molecules can not be compressed. They have fixed volume and take the shape of the container.

C. neon gas : The molecules in gas are very less tightly packed as inter molecular forces are very low. There is large vacant space between the particles and thus the molecules can be compressed. They neither have fixed volume nor a fixed shape.They occupy complete volume of the container in which it is put.

D. sugar crystals: The molecules in solid are very tightly packed as inter molecular forces are very high. There is very less space between the particles and thus the molecules can not be compressed. They have fixed shape and volume.

aquifers are bounded above and below by impermeable rock. the driving force of groundwater movement in confined aquifers is pressure, rather than gravity.

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

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