After watching this video, I hope! You will be able to create google recaptcha for your wordpress contact form 7 even the entire website. The re-captcha will help your site from spam and some hacking activity.
reCAPTCHA protects your website from fraud and abuse. @Source Google
reCAPTCHA uses an advanced risk analysis engine and adaptive challenges to keep malicious software from engaging in abusive activities on your website. Meanwhile, legitimate users will be able to login, make purchases, view pages, or create accounts and fake users will be blocked.