Is the word rice a concrete or abstract noun?

The noun 'rice' is a concrete noun as a Word for a physical substance.

A concrete noun

Anything able to be experienced the by human senses of sight, hearing, taste, touch, smell (chair, air, pear).

An abstract noun

Th opposite to a concrete noun, a Word for something that your five senses cannot detect. You can't see them, hear them, smell them, taste them, or touch them. They are Words for things that you know, learn, think, understand, or feel emotionally.