Consider the heat equation of the temperature of a solid material. The Dirichlet boundary conditions means to fix the

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

pie chart because it is in percents ( % )

2b2t

explanation:

2b2t