Explain how elements are arranged on the periodic table. in other words, explain why they are not just listed in one long list, but are instead grouped into rows and columns. also, describe the placement of metals, metalloids, non-metals, and noble gases on the periodic table.

The answer for #3 is c but i don't know why

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.

Identify a specific example for each type of technology