Answer is 4 ½ billion.
Scientists think the earth's age is 4 ½ billion. This calculation is based on the radioactive dating. Since the formation of the earth, the time period has been divided into 3 major geological time periods as eon. They are phanerozoic, proterozoic and archean.
Answer:
Ne, Ar, and Kr are gases at STP, unreactive, and are generally monatomic.
Explanation:
they are unreactive and monoatomic and thats why have a very low boiling point.
Lead has a different chemistry than most biological metals, but it can mimic some of them, such as calcium, iron, and zinc, because it tends to form 2+ ion like other metals, and these can be formed inside the body. Due to it different chemistry, lead prevents normal functioning of the enzymes it binds to, inhibiting them and poisoning the body.
Gold rarely forms ions, unless under extreme conditions that are not present in the human body. Gold ions, when ingested, are actually very toxic, so gold poisoning is possible. But because gold are so rare, gold poisoning is also a rare phenomenon.
