I believe it is dissecting
Answer:
Q2->They all form acids when combined with hydrogen. They are all fairly toxic. They readily combine with metals to form salts.
Q3->Because their outermost orbit is complete. In Mendeleev's original periodic table there was no place reserved for noble gas. They were discovered in end of 19th century. So Mendeleev created zero group without disturbing original periodic table.
Explanation:
Answer: B. Individuals and agriculture
Explanation:
Embryo should be the answer
Around what time that they became extinct. They measure the amount of decay on the bone, and it gives them pretty accurate info