Looks like the downloaded file is corrupted.
Make sure you download Google Chrome from the official webpage and that your internet connection is fine.
Also, restart your Mac before attempting to download the file once again.
Also, you can try the troubleshooting steps for Safari below.
If you have problems opening webpages, take a look at these troubleshooting techniques suggested by Apple.
https://support.apple.com/en-us/HT204098
Go to Safari menu (At the very top right side of your screen next to Apple icon), choose "Quit Safari"
press "Shift" button and while holding this button on your keyboard single click on the Safari icon on your Dock.
Open Safari - Preferences - Privacy - Remove All Website Data.
Open the Go menu with Option (Alt) key pressed - Library - locate Safari folder and move it to your desktop. Restart your Mac, open Safari and delete the folder from your desktop.