Are these correct? ILL MARK YOU BRAINLIEST

Yes

Step-by-step explanation:

1) Cos 300 = Cos (360 - 60) = Cos 60    {Cos 360 - theta = Cos theta}

                                              = 1/2

Sin 300 = Sin (360 - 60) = -Sin 60 =

3) 3π/4 = 3*180/4 = 135

Cos 135 = Cos (90 + 45) = -Cos 45 =

Sin 135 = Sin (90 + 45) = Sin 45 =

 Shows valence electrons:  Lewis structure

 2. Shows chemical composition but no structure: Molecular    

3. Is used most for hydrocarbons; shows lines and functional groups only: Skeletal

Explanation: