Gas is one of the four states of matter, along with solid, liquid, and plasma. Gas has a large separation between its atoms or molecules. Usually the matter in gas is so spread out you can see right through it!
Seeds are key to the reproduction of many plants. They are a plant embryo with a protective coating. When they find a suitable home with the right soil, water, and temperature they will sprout into a seedling!
Salt on a molecular level, is tiny crystals of alternating sodium and chloride atoms. These atoms form tiny cubes. Those cubes stack into bigger cubes and so on until you have grains of table salt. Look closely and you can see all the little square edges!