What do these symbols mean in terms of an air mass?
m:
c:
P:
T:

cT= continental Tropical

cP=continental Polar

mT=maritime Tropical

there is also :

mP=maritime Polar

cA=continental Arctic

c(continental)=dry/not very humid

m(maritime)=wet/humid

T(Tropical=warm

P(Polar)=cold

A(Arctic)=very cold

these are all terms used during a weather topic

Explanation:

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.

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3