Is lettuce and tomatoes a mixture?

Here's why:

* No new substance is formed: When you combine lettuce and tomatoes, you don't create a new ingredient. They remain lettuce and tomatoes.

* Components can be separated: You can easily pick out the lettuce leaves and the tomato slices from the mixture.

* Heterogeneous: The lettuce and tomatoes are not uniformly distributed throughout the mixture. You can see distinct pieces of each.

Therefore, lettuce and tomatoes together are a heterogeneous mixture.