The answer to this problem is Beryllium is an alkaline earth metal.
First write all of the compounds/atoms in either side then fill in existing values and balance
Na- 1
Br- 1
Ca- 1
Cl- 2
Na- 1
Cl- 1
Ca-1
Br-2
Balance to get
2NaBr+CaCl2=2NaCl+CaBr2
Permeable materials for what
