Apotassium isotope has a half-life of 1.25 billion years. given that scientists estimate earth's age to be 4.6 billion years, what is the most likely percentage of parent to daughter isotopes of this element currently existing on earth?

a. less than 10 percent
b. 25 percent
c. 50 percent
d. more than 75 percent

*will mark brainliest* certain species of are now recognized as indicators of environmental pollution. a. lichen b. mushroom c. yeast d. none of the above

Sammi is studying the interaction of the digestive and circulatory systems in the human body. she has listed various processes that occur in each of the systems. put the processes in order to describe the interaction between these two systems. tiles nutrients diffuse through the villi of the small intestine. digestive processes break nutrients down in the mouth, stomach, and small intestine. blood is pumped through the circulatory system to deliver nutrients to other organs. nutrients are ingested at the mouth. nutrients enter the capillaries of the circulatory system. sequence

What are the headings of a data table