<span>Equilibrium is your answer i believe.
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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:
Organism, population, community, ecosystem, biosphere
They give us the energy we need to move and to speak and to live they do that for all the organisms on earth
Vertebrata
Vertebrata is a group that contains various organisms which possess vertebrae (backbones). Animals that belong to the group are called vertebrates, and they include mammals, birds, fish, amphibians, and reptiles. The backbones in the animals extends from the head to the tail, and it encloses and protects the main nerve cord. The body of vertebrates is divided into trunk, and tail regions. They also possess a unique tube shaped brain, a distinct head, and three pairs of sense organs.