Question

write the formula for the following covalent compound: selenium hexachloride

Explanation:

Step1: Identify elements and prefixes

Selenium (Se) has no prefix (so 1 atom), "hexachloride" means 6 chlorine (Cl) atoms (prefix "hexa-" = 6).

Step2: Combine elements with subscripts

Write Se first, then Cl with subscript 6.

Answer:

$\ce{SeCl_{6}}$