1. The problem asks to factorize the expression $-2a^2$. 2. Factorization means expressing the expression as a product of its factors. 3. Here, $-2a^2$ is already a product of $-2$ and $a^2$. 4. So the factorized form is simply: $$-2a^2$$ 5. There is no further factorization possible since $-2$ is a constant and $a^2$ is a power of a variable. 6. Therefore, the answer is $-2a^2$. This completes the factorization.