What are the approximate carbon dioxide emissions to date?

Fossil fuels have relatively less of which isotope of carbon?

Every carbon atom in diamond is bound to four other carbon atoms in the form of a _?

What are the products of burning hydrocarbons in air?

0.5 trillion

1.5 trillion

What is the approximate atomic mass of carbon?

Which is the most abundant element in the human body?

What is the process by which elements heavier than boron are created?

CH4 is the chemical formula for which compound?

Rank natural gas, wood, hydrogen, and coal in descending order for energy density by mass.