Can I enter China without a visa if I have an Argentinian passport?

You cannot enter the country without a visa. You need to see the visa when passing through customs.

A visa is an endorsement or stamp by a country’s sovereign authority on the passport or other travel documents held by its or foreign citizens to indicate that they are allowed to enter or exit the country’s territory or pass through the country’s territory. It can also be said to be an endorsement-style certificate issued to them. In summary, a visa is a document issued by a country's entry-exit management agency (such as the Immigration Bureau or its consulate abroad) to express approval for entry to foreign citizens.

To put it simply, passports are issued by the Public Security Bureau (government), and visas are approved by other countries’ embassies in China. The visa is affixed inside the passport. Without the passport, you cannot apply for a visa. But with a passport, you may not be able to apply for a visa. For Chinese people, basically they need to apply for a visa when going abroad. Just having a passport is just an extra ID card. So you still need a visa to go abroad.