Learn Italian: Il gas esce velocemente, perciò l'esperimento è pericoloso. - The gas comes out quickly, therefore the experiment is dangerous.

Yes, you can. perciò, quindi, and dunque all mean "therefore" or "so", and they are used to show the result or consequence of something. In this sentence, you can swap perciò with either of the other two without changing the meaning.

Where does the verb esce come from?

It is the third-person singular form of the irregular verb uscire (to go out or to exit). uscire is a bit tricky because the u changes to an e in most of its present tense forms, such as io esco (I go out) and lui/lei esce (he/she/it goes out).

How is the word velocemente formed?

It is an adverb formed by taking the adjective veloce (fast or quick) and adding the suffix -mente. In Italian, adding -mente to an adjective is just like adding "-ly" in English. So, veloce becomes velocemente (quickly).

Why does pericoloso end in -o?