Answer:
Here's what I get.
Explanation:
(a) F, Cl, Br, and I are called halogens (salt formers)
(i) They are placed in Group 17, the Group just before Group 18 (the noble gases), because they need just one more valence electron to get a noble gas electron configuration.
(ii) At room temperature, iodine is a lustrous, purple-black solid that melts to form a deep violet liquid at 114 °C.
The circumstances when scientists use observational research and opinion based research is when they include animals or things that cannot control for a product. Observational research is a type of research which only observes ongoing behavior and studies about it and the results only rely on the behavior observed.
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