Regardless of whether or not the first one is "correct", my advice would be to use the second one. As a general rule, the predicate in English goes in the following order: verb, direct object, prepositional phrases. The "rule" is not strict, but if you break it more than a few times in a conversation, you'll certainly sound foreign.

The second sounds more natural. The first isn't wrong and could be okay colloquially. That'd depend on your tone and the context. Hope this helps! :)

"Explain(ing) something to someone" is pretty much the only way that sounds right fluid. The object pronoun sounds better after the noun in the sentence.

Hello, The second sentence is always correct. The first sentence is a departure from the grammar rules. I hope this answers your question. If you’d like to practice speaking. I’d be happy to help you develop a study plan. Feel free to view my teaching profile and class offerings and send me a message if you think I can help you. Regards.

I think both are correct, they can make sense for me.