Can a Apple Pencil 2 work with a iPad 7th generation??

No. The second generation Apple Pencil is not compatible with the iPad7. Magnets are used by the iPad for various functions - such as detecting when a compatible cover is open or closed.

Here is the full compatibility list for Apple Pencil and iPad:

Apple Pencil (2nd generation)

You can use Apple Pencil (2nd generation) with these iPad models: 

• iPad Air (4th generation)
• iPad Pro 12.9-inch (3rd generation) and later
• iPad Pro 11-inch (1st generation) and later

Apple Pencil (1st generation)

You can use Apple Pencil (1st generation) with these iPad models:

• iPad (8th generation)
• iPad mini (5th generation)
• iPad (7th generation)
• iPad (6th generation)
• iPad Air (3rd generation)
• iPad Pro 12.9-inch (1st or 2nd generation)
• iPad Pro 10.5-inch
• iPad Pro 9.7-inch

Not sure which iPad you have? Identify your iPad model.

Sorry no, as per this compatibility list:--> Apple Pencil compatibility - Apple Support

Regards

Giulio