Is a daisy a example of radial balance? What is negative space and occult balance?

Yes, a daisy is an example of radial balance (and symmetry). Negative space is the space around an object. Think of a silhouette, the space around the silhouette is negative. A coffee mug...The space inside the handle as you look at the mug is negative space. Your hand, with fingers spread...the space in between your fingers is negative space. Occult balance is where the background (usually negative space) dominates the composition.