A rock sample has 25% of its original radioactive element and the half-life of the element is 1 million years. How old is the sample?
A.)2 Million Years
B.)0 1 Million Years
C.)500.000
D.)50,000

c 500000

Explanation:

the half was 1000000 so it's 2000000 and 25% of that is 500000

both anaerobic and aerobic respiration use glucose (or other carbohydrates), proteins and lipids to produce atp and nadh. cell uses those energy molecules, obtained from food and   breaks them down during the chemical reactions of respiration. in anaerobic respiration, nadh is regenerated to nad+ by enzymes lactate dehydrogenase (lactate is produced, e.g. in muscle cells) or by alcohol dehydrogenase where ethanol is produced (alcohol fermentation), while in aerobic respiration, electrons from nadh are deposited in the mitochondria to regenerate nad+ (electron transport chain. anaerobic respiration produces 2 atp per molecule of glucose compared to aerobic respiration where about 38 atp molecules are produced.

equal distribution i think.