For each of the pictures below, decide what element it comes from and circle atom or ion. Then write the chemical symbol and the charge if any.

What is the h+ concentration for an aqueous solution with poh = 4.01 at 25 ∘c? express your answer to two significant figures and include the appropriate units.

An empty fuel tank can still contain and therefore can be even more dangerous than one full of liquid fuel.

Use examples from the article to explain one positive and one negative effect that chemistry has had on society.