What are the characteristics of a substance in the gas phase?
made up of particles packed closely together, having both definite shape and definite volume
made up of particles packed relatively close together, having an indefinite shape but a definite volume
made up of particles that are far apart from each other, having both indefinite shape and indefinite volume
made up of positively charged particles and negatively charged electrons, having indefinite shape and indefinite volume

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.

if it's not useful, feel free to report for mistake in answer.

air

in a tire you fill a tire with air

then a couple days later you check the air pressure in the tire

hope this mark me brainliest