The sentence "Jon spent too much time at the baseball game, and his mom was angry" is a compound sentence. It contains two independent clauses, "Jon spent too much time at the baseball game" and "his mom was angry," which are joined by the coordinating conjunction "and"
Simple, compound, and complex are three types of sentence structures in English grammar.
Simple Sentence: A simple sentence contains one independent clause (a group of words that expresses a complete thought) and no dependent clauses (a group of words that cannot stand alone as a sentence). Example: "I like to play tennis."
Compound Sentence: A compound sentence contains two or more independent clauses joined by a coordinating conjunction (and, or, but, so, yet, for, nor) or a semicolon. Example: "I like to play tennis, and my brother likes to play soccer."
Complex Sentence: A complex sentence contains one independent clause and one or more dependent clauses. The dependent clauses are introduced by a subordinating conjunction (such as although, because, since, when, while) or a relative pronoun (such as who, whom, whose, which, that). Example: "Although it was raining, we still went to the beach."