Just what is chemistry, anyway, and why is it so important?
Chemistry is when you can sense attraction zipping back and forth between two characters. It's when their connection is so palpable, you can feel it leaping off the page, and it's an important element in romance writing. People read romances because they want a really good love story, and a really good love story isn't really good without chemistry.
So how do we create that in a book?
The best way that I've found is to show everything the point-of-view character is thinking and feeling. Let me show two examples that I've just made up to demonstrate.
The new boy came in and took the desk next to me. He was pretty cute, with green eyes and a dimple. "Hi," he said as he sat down. "I'm Dean."
"Hi," I mumbled, dropping my pencil. We both reached down to pick it up, and our hands brushed.
When the new boy came in the classroom, I couldn't take my eyes off him. There was something about the way he moved that made my stomach flip-flop. He walked over to the desk next to mine-holy cow, he had three other desks to choose from, and he chose the one by me-and I noticed his green eyes and his dimple. Green eyes. I love green eyes.
"Hi," he said as he sat down. "I'm Dean."
Did he mean James Dean, total hottie Hollywood icon? My hands started to shake, and I wished I knew how to stop them. "Hi," I mumbled, dropping my pencil. Oh, that was smooth. That was really smooth. I reached down to get it, and so did he. Our hands brushed, and it was like fire racing up my arm. Did he feel it too, or was I the only one?
Notice how in the first example, we read about everything that happened. In the second example, we read everything she thinks and feels about what happens. Which one allows us to start feeling chemistry? The second one, of course, because chemistry is largely emotional.
Allow me to show you a clip.
This is, of course, from Somewhere in Time, which is full of scientific flaws but is still one of the most romantic movies ever. Ever! Ahem. Anyway, notice all the nuances in this clip as you're watching.
First, as they're coming down the hall, they're both feeling awkward. This isn't because they don't like each other - it's because they like each other so much, they don't know what to do with themselves. When they enter her room, notice how he's looking at her back. There's so much he wants to say, but he's worried about messing it up. He takes some deep breaths. In the meantime, she's trying to control her own reactions. She knows she has feelings for him, but it's illogical. She's a businesswoman. She doesn't have time for this silliness, but he's Christopher Reeve, and he's so dang good-looking ...
When he reaches out and touches her, she gives a slight shake of her head. This can't work - it's impossible. Notice that he doesn't just grab her and plant one on her. He touches her cheek. He's trying to convince her, still giving her the chance to say no, but doing everything he can - while remaining a gentleman - to encourage her to share his feelings. She battles within herself, but then finally gives in to that battle, and then he kisses her.
And through the whole thing - the lead-up and then the kiss - the viewer's heart is in their throat. Will they kiss? Won't they kiss? And then they do, and it's awesome, and then dang. There's a knock at the door.
The point is this. We were allowed to see the build-up. The scene moved slowly enough that we could tell exactly what they were both thinking and feeling, and that's what made the kiss so awesome. If he'd just grabbed her and kissed her as soon as her door was closed, okay, it would have been a nice kiss, but that mounting chemistry is what brought it the power it needed, and movie buffs call that one of the most romantic kisses in cinema history.
Of course, I'm comparing a movie to a book, so they aren't the same thing, but we can create the same types of reader reactions through our writing. When there's an emotionally charged moment, slow down and give all the reactions and let the reader bask in the moment. And then they'll sigh and go back and read it again. :)