LD50

LD50 stands for "Lethal Dose 50" which means amount of a substance that will kill 50% of the animals tested. It's like when you play a game with 10 friends and 5 of them lose, that's 50%. In science, they test animals, like mice or rats, to find out how much of a chemical or medicine is needed to cause death in half of the animals tested. So if they test 10 rats and 5 die from a certain amount of a chemical, that amount is said to be the LD50 dose.

Scientists use LD50 testing to figure out if a substance is harmful or not. They make different doses of a substance, and give it to a group of animals. They watch the animals closely, and if too many of them get sick or die, they may stop the testing. They then use the LD50 amount to determine how much of the substance is safe to use in factories, medicine, or in our environment. So, LD50 testing helps to make sure that people and animals are safe from harmful substances.