What is the building block of matter? Question : What is the building block of matter? Answer : Atom is the building block of matter. 7 little words Two-door Plymouth model Bruise around the eye Roosting rod 7 Little Words Easy mark 7 Little Words Hockey footwear 7 Little Words Hairstyle 7 Little Words Painter Jackson 7 Little Words 1940s Fairey aeroplane Kind of gull 7 Little Words Insignificant person 7 Little Words