MATERIALS

Brittle

hard and easily broken

compact

to make something smaller or firmer by pressing it, or to become smaller or firmer like this

crumb

small piece of e.g. bread or cake

dense

tightly packed in

dilute

To make a liquid less concentrated

dissolve

to make or become liquid

firm

solid but not hard

flake

to come off a surface in small flat pieces

friction

the physical force that makes it difficult for one surface to move over another

grain

Seed of a cereal grass

A very small individual piece of a substance such as sand, salt or sugar

gravity

the force that attracts a body toward the center of the earth, or toward any other physical body having mass.

grind

to break something into small pieces, or powder, by using a machine, or by crushing it between two hard surfaces

hollow

empty inside

mould

shape or form

opaque

impossible to see through; preventing the passage of light

pat

to touch someone or something gently and usually repeatedly with the hand flat

pile

a group of things that are put one on top of another

polish

to make shine; to make something better

scratch

cut, scrape, or wear away the surface of

scrub

to clean something by rubbing it hard with a brush

speck

a very small spot

stack

pile

squash

to damage something by pressing or crushing it and making it lose its normal shape

stiff

difficult to bend or move, harsh

stroke

to gently move your hand over skin, hair, or fur

substance

a particular type of solid, liquid, or gas

synthetic

artificial

stuff

to push something into a small space, often quickly or in a careless way

materials, supplies, or equipment

opaque

(a) Impossible to see through; preventing the passage of light