Answer:
In uranium-lead dating, for instance, the radioactive decay of uranium into lead proceeds at a reliable rate. Based on the very old zircon rock from Australia we know that the Earth is at least 4.374 billion years old.
And that's how after rounding we know that earth is 4.5 years old.
<span>One way to repel the insect pests in an apple orchard without using chemical pesticides is by planting marigold near it. Marigold contains a compound known as Pyrethrum. It produces a certain smell that even gardeners doesn't like. Pyrethrum is also one of the components in making insecticides.</span>
The week after her period is when she is most likely to become pregnant. this is due to the ovulation that occurs during that time.
They are called as Noble gases. Hope it helped you. Please mark as the brainliest answer if it helped.