Question

the image shows several orange triangular cards with chemical formulas and names, such as co, fecl3, ca3n2, na3po4, fe(no2)3, n2o, mgo2, kcl, fe(no3)2, ni3, cbr4, fecl2 (labeled as potassium chloride magnesium monoxide), n2, pcl3, tin(iv)oxide, tin(ii)oxide, magnesium oxide, etc. (note: some text may be reversed or misread due to orientation, but the main content is chemical formulas and compound names on triangular cards.)

Explanation:

Step1: Identify the correct formula - Magnesium Oxide

The correct chemical formula for magnesium oxide is \( \text{MgO} \) (since magnesium has a +2 charge, \( \text{Mg}^{2+} \), and oxygen has a -2 charge, \( \text{O}^{2-} \), so they combine in a 1:1 ratio). Looking at the triangles, we need to find the one with the correct formula and name.

Step2: Locate the correct triangle

Among the triangles, the one with "magnesium oxide" and the formula \( \text{MgO} \) (the triangle at the bottom middle, labeled "magnesium oxide" with formula \( \text{MgO} \)) is the correct one as it has the proper chemical formula and name matching. Other triangles have errors: for example, some have incorrect formulas (like wrong subscripts or wrong element combinations) or mismatched names and formulas.

Answer:

The triangle labeled "magnesium oxide" with the formula \( \text{MgO} \) (the bottom - middle triangle)