O
Which of the following happens during a chemical change? Check all of the boxes that apply.
One atom or more changes into atoms of another element.
New substances with different properties are formed.
Solids, liquids, or gases may form.
Reaction mixtures always give off some heat.
Reaction mixtures always need to be heated.
O
O

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.