‘A’ is an element having four electrons in its outermost orbit. An allotropes ‘B’ of this element is used as a dry lubricant in machinery and in pencil leads. So:
i. Write the name of element ‘A’ and its allotropes.
ii. State whether ‘B’ is a good conductor or non-conductor of electricity?
‘E’ is an element which reacts with oxygen to form an oxide E2O. An aqueous solution of E2O turns red litmus blue, so:
i. What is the nature of oxide E2O ?
ii. Write the name of element ‘E’.
Write any three differences between metals and non-metals with respect to their physical properties.
Name any three parts of te female reproductive system in human beings. Write one function of each.
Write names of different parts of human digestive system and explain functions of any three parts.