a fossil was analyzed and determined to have a carbon-14 level that is 50 % that of living organisms. the half-life of c-14 is 5730 years. how old is the fossil?

The image shows ekgs of a person with normal heart waves and of a person having tachycardia. based on this image, what kind of condition is tachycardia? a. the heart beats abnormally fast. b. the heart beats abnormally slow. c. the right atrium of the heart stops working. d. the left ventricle pumps less blood to the aorta.

Why are scientists concerned about the depletion of the ozone levels in the stratosphere?

Match the reproductive structures based on their function and the system to which they belong. egg ovary sperm vas deferens vagina fallopian tube testis urethra