Why does the level of carbon dioxide affect the global temperature?

Seawater contains approximately 3.5%nacl by mass and has a density of 1.02 g/ml. what volume of seawater contains 7.5 g of sodium?

What is the nature of the ca-cl bond in a molecule of calcium chloride (cacl2) if the electronegativity value of calcium is 1.0 and that of chlorine is 3.16?

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