Will mark Brainless you have a rock containing the element x which has a half life of 1000 year. no daughter product were originally present. however now there is an equal amount of element x and its daughter product. How old is the rock?? Anyone can help? Thank you guys!

Which of the following is an example of competition a. the leaves of a tree prevent a small shrub from getting sunlight. three species of birds feed a different heights in the same tree. b. three species of birds feed at different heights in the same tree c. zebra and giraffe’s feed on different grassland plants d. cats living in two different homes eat the same brand of cat food.