Science fair projects for 7th grade ideas?

Some familiar products contain some of the same types of atoms. for instance, the chemical formula for baking soda is nahco 3. the chemical formula for liquid bleach is naclo, and the chemical formula for table salt is nacl. which choice best describes why these three products have some of the same types of atoms in common?

Is 343 in the sequence -5, -2, 1, 4, 7

Rank substituents in order of their priority when assigning the e or z label to an alkene. i, ch2i , h, ch2ch2cl, f