you see a structural formula and which the symbols for elements are connected by a long Dash you can assume that the chemical bonds in the compound are

When you see a long dash joining two elements in the structural formula of a chemical molecule you can assume that the chemical bonds in the compound are simple bonds.

In the representation of chemical molecules long dashes are used to represent simple bonds since these bonds are longer than double and triple bonds, which are represented by = and ≡ respectively.

Convalent