(E)-3-Phenyl

[Kimberly Waszak 2G]

In the orange course reader on page 60, they name C6H5CHO as (E)-3-Phenyl-2-propenal (cinnamaldehyde).
First, how can we tell that it's trans/E from just the name and line structure? Is this just a visual thing I have to understand?
Also, where does the name "Phenyl" come from?

Thanks! :)

[Samuel Yang]

You can tell it is E by looking at the middle double-bond carbon. This does not apply for terminal double bonded carbons.

When you identify the double bonded carbon, both branches go in opposite directions, so that is why it is E.