Please i need someone to answer this for me. its urgent A scientist is trying to determine the age of a rock layer in O points a canyon using Uranium-234, an isotope of Uranium. It has a half-life of about 2,000 years. There originally was 400 radioactive atoms of Uranium-234. If the rock layer tested has 100 radioactive atoms of U-234 left, how many half lives have passed AND how old is the rock layer?

1. true.2. true.3. true.4. false.5. true.the concept of darwin's theory of evolution involves the idea that there are limited resources in a given living environment and that the organisms which live within have variations in their genetic make up due to random mating. the ones with beneficial genetic variations can express certain traits which give them an upper hand in surviving and reproducing in the said environment compared to ones who may have a more disadvantageous variation in traits. over time, the organisms with an upper hand will survive and reproduce more frequently and pass on their beneficial genes while the others die. the result is evolution, where we observe (usually, but not always) eventually, phenotypic distinct changes.

It will increase hope this heloed

The general characteristics of blood are red iron and heat the three types of formed element cells are blood cells, white blood cells and , iron cells