state border.
State boarder
on a map,what do black lines between states usually represent? state boundries
On maps, black lines between states represent boundaries or borders, where one state stops and the others starts. These are also called state lines.
the Borders
equilibrium between two states
Usually they indicate the borders between the states.
I think you're talking about the borders of the states. Sometimes, between countries, if normal borders are solid lines and you see dotted lines in some places, you can see in the map key that the dots might mean a disputed border (like currently for Somalia).
State boarder
usually it's state boundaries
In most cases the black lines which are between the states point out the border between different states, telling the map reader when the you are in a different state.
The black lines mean it is a state boundary.
The lines in a structural formula represent the chemical bonds. These bonds are attractive forces between atoms that allow the formation of chemical substances.