Question

determine the name for each compound from its formulas. k₂o: ni₂se₃: n₂o₅:

Explanation:

Step1: Identify cation and anion for $K_2O$

$K$ is potassium (cation) and $O$ is oxide (anion).

Step2: Name the compound

The name is potassium oxide.

Step3: Identify cation and anion for $Ni_2Se_3$

$Ni$ is nickel (transition - metal cation) and $Se$ is selenide (anion). Nickel has a +3 oxidation state here, so it's nickel(III) selenide.

Step4: Name the compound for $N_2O_5$

For binary covalent compounds, use prefixes. $N$ is nitrogen and $O$ is oxygen. The prefix for 2 is "di -" and for 5 is "penta -". So it's dinitrogen pentoxide.

Answer:

Potassium oxide
Nickel(III) selenide
Dinitrogen pentoxide