Thoughts on Vayakhel

1) There is lots of gold, silver, and bronze being discussed in the plans for the Mishkan. It looks confusing, but there is a very simple pattern for determining which materials everything is made from.

• The Mishkan, and the furniture inside it, is gold (or wooden and coated with gold).
  
• Furniture outside the Mishkan is bronze.
  
• Various connective materials, both inside and outside the Mishkan, are silver.
  

(As a physics major, I speculated that silver might be stronger than gold or bronze, and was therefore chosen to connect things. Looking online, I found that silver is slightly stronger than gold but weaker than bronze. So this does not seem to be the main reason for the choice of silver.)

2) A little chemistry, history and linguistics. "Bronze" and "brass" are both copper with other metals mixed in (tin and zinc respectively), which makes them stronger. By the time of the Torah the manufacture of bronze (at least) was well known and much preferable to just using copper. So even though the Biblical word "nachoshet" means "copper" in modern Hebrew, the substance used in the Mishkan was almost certainly bronze.

3) The parts of the Mishkan are listed in different orders in God's command (parshat Terumah) and in the work description (Vayakhel and Pekudei). But there's a simple, logical reason why in each case the text uses the order that it does.

• In God's command, the parts are listed thematically. For the most part, this means from most to least important - the ark, then the other items within the Mishkan structure, then the structure itself, then the items located outside. (See here for an explanation of exceptions to this rule.)
  
• In the work description, the parts are listed in the order they were made - the structure first, then the items inside it, then the items outside it. The structure had to be made first, because you needed a place to store the ark etc. once they were made.