Most of the emissions of greenhouse gases (GHG) come primarily from burning fossil fuels (coal, hydrocarbon gas liquids, natural gas, and petroleum) for energy use and the major greenhouse gas is of course carbon dioxide (CO2) which comes from burning fossil fuels and land-use change.
But methane (CH4) and nitrous oxide (N2O), which mostly come from agriculture and waste, are also significant GHGs and shouldn't be discounted.
Which elements are most abundant in living organisms?
A) oxygen, nitrogen, carbon, hydrogen, sulfur, and phosphorus
B) carbon, potassium, iron, magnesium, hydrogen, and nitrogen
C) hydrogen, carbon, calcium, potassium, oxygen, and phosphorus
D) oxygen, calcium, phosphorus, sodium, hydrogen, and carbon
A) oxygen, nitrogen, carbon, hydrogen, sulfur, and phosphorus
B) carbon, potassium, iron, magnesium, hydrogen, and nitrogen
C) hydrogen, carbon, calcium, potassium, oxygen, and phosphorus
D) oxygen, calcium, phosphorus, sodium, hydrogen, and carbon
Answer & ExplanationAnswer: A) oxygen, nitrogen, carbon, hydrogen, sulfur, and phosphorus
Explanation:
Living organisms often contain trace amounts of several elements, but the most abundant ones are oxygen, carbon, hydrogen, nitrogen, calcium, sulphur and phosphorus.