Please help me with letters A-F on this worksheet. i don’t get anything on it.

What is the percentage by mass of silicon (si) in iron aluminum silicate (fe3al2(sio4)3)?

Asap! how do you lengthen a pattern piece? (family and consumer science, sewing)

The covalent compound acetylene, which is the fuel of the oxyacetylene torch used by welders, has the molecular formula c2h2. the covalent compound benzene, a commercial solvent, has the molecular formula c6h6 each of these covalent compounds contains carbon and hydrogen atoms in a one-to-one ratio. would it be correct to write the chemical formulas of each as ch? explain.