Twitter users voiced a mix of excitement, worry and skepticism on Monday about Elon Musk’s takeover of the site. And perhaps unsurprisingly, the reaction reflected the divided political and cultural nature of the running conversation on the platform.

The news generated multiple trending topics on Twitter, including Mr. Musk’s name and the hashtags #RIPTwitter and #twittersold.

Many raised questions about Mr. Musk’s plans for the company.

Jack Dorsey, a founder of Twitter who twice served as its chief executive and is on the company’s board, tweeted a link to the Radiohead song “Everything in Its Right Place” and thanked Mr. Musk “for getting the company out of an impossible situation.”

“This is the right path,” he added. “I believe it with all my heart.”

John Scott-Railton, a researcher at the University of Toronto’s Citizen Lab, wrote: “Does Musk plan to let Trump back on the platform? Will he look at the DMs of perceived enemies?” he asked, referring to Twitter’s private, direct messaging feature.

Officials and policymakers, in the United States and beyond, shared their opinions, showing how the site had become a sort of political battleground.

Senator Ted Cruz, Republican of Texas, posted a poll for Twitter followers, asking: “Is Elon Musk’s purchase of Twitter a good thing?” The two answer choices — “Yes” and “No, I hate free speech” — seemed to suggest his support for the move.

Gov. Ron DeSantis, Republican of Florida, wrote that Elon Musk’s offer to buy Twitter was “a good deal for shareholders and raises the prospect that the platform will be a place where free speech can thrive, not a tool for narrative enforcement.”

Nigel Farage, the British politician who pushed for a hard-line break with the European Union, wrote on Twitter: “Great news. Many congrats, Elon Musk. Let’s hope this marks a turning point.”

On the other side of the political spectrum, lawmakers were concerned about Mr. Musk’s motives and his wealth. “Tax the rich,” wrote Representative Pramila Jayapal, Democrat of Washington. “It’s absurd that one person can afford to buy Twitter for more than $40 billion while working families across this country have to choose every day between buying groceries or their prescription drugs.”

Senator Elizabeth Warren, Democrat of Massachusetts, shared a similar message: “This deal is dangerous for our democracy. Billionaires like Elon Musk play by a different set of rules than everyone else, accumulating power for their own gain. We need a wealth tax and strong rules to hold Big Tech accountable.”

Robert Reich, a labor secretary under former President Bill Clinton, touched on many progressives’ fears when he wrote on the site: “When billionaires like Elon Musk justify their motives by using ‘freedom,’ beware. What they actually seek is freedom from accountability.”

In the business world, allies of Mr. Musk were optimistic. Keith Rabois, a venture capitalist who worked at PayPal with Mr. Musk, earlier on Monday posted, “Ok, now I can finally start to Tweet.”

The entertainment world also took notice. Ice Cube, the rapper and actor, wrote on Twitter: “Free at last!” He tagged Mr. Musk and wrote, “Take off my shadow ban homie,” referring to a subtle form of limiting a user’s posts without letting them know.

Others voiced fears about harassment on the platform, after Mr. Musk said he would change content moderation. Users of social media sites like Twitter, Instagram and TikTok have long complained that harassment is rampant, even with current content moderation efforts.

Dr. Peter Hotez, a vaccine researcher who has frequently spoken publicly about receiving threats online after speaking about pandemic safety measures, has said he is forced to block two to four people or groups most days “due to their menacing tweets or threats.” He said on Twitter that he would seek an alternative to the site if the hateful responses to him significantly increased.

And some voiced concerns that people would leave the platform. “This is like a season finale of Twitter,” wrote Jane Manchun Wong, a technology blogger and researcher.

But others called quitting Twitter a dramatic response. “I doubt anyone’s really leaving Twitter,” read a post from the Twitter account for Spawn Wave, a YouTube platform mostly for tech reviews and video game content. “There’s just too much stuff for us to complain about nowadays.”