When the metallic element sodium combines with the nonmetallic element bromine, br2(l), how can you determine the chemical formula of the product? how do you know whether the product is a solid, liquid, or gas at room temperature?

The answer is

1)The chemical formula of the product is NaBr

2) The product is a solid

The explanation:

The ions of the two reactants are Na{+} and Br{-}, so the formula of the product is NaBr.  

and when the NaCl is a solid a room temperature. and when NaBr has similar properties to NaCl, so NaBr is a solid at room temperature too.

so our chemical formula for the product is NaBr and It's a solid at room temperature.

2 Na + Br2 → 2 NaBr

14 days is the half-life of phosphorus-32