Complete the following crossword puzzle (Figure)
Across
(1) An element with atomic number 12
(3) Metal used in making cans and member of group 14
(4) A lustrous non-metal which has 7 electrons in its outermost shell
Down
(2) Highly reactive and soft metal which imparts yellow colour when subjected to flame and is kept in kerosene
(5) The first element of second period
(6) An element whihc is used in making flurescent bulbs and is second member of group 18 in the modern periodic table
(7) A radioactive element which is the last member of halogen family
(8) Metal which is an important constituent of steel and forms rust when exposed to moist air
(9) The first metalloid in modern periodic table whose fibres are used in making bullet-proof vests

Explanation