Why do molecules combined into chains?
Answer:
I think the answer is test tube 2
Halogen--Florine
Chalogen-- Oxygen
Alkali Metal-- Sodium
Boron -- Metalloid (atomic symbol B)
Lanthanide series-- (Number 57-71 on periodic Table) Example: Cerium #58
Alkaline Earth Metal--Magnesium
Transition Metal-- Gold, Iron, Silver. Etc... (Middle section of a period table)
Nobel Gas--Helium
Answer: St Br2
Explanation: Br has only one valence electrons and Sr has 2 valence electrons this is why we need 2 atoms of Br to for an ionic compound with 1 atom of Sr.
