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:DNA has three types of chemical component: phosphate, a sugar called deoxyribose, and four nitrogenous bases—adenine, guanine, cytosine, and thymine. Two of the bases, adenine and guanine, have a double-ring structure characteristic of a type of chemical called a purine.
Explanation:
