An atom of an element X may be written as 
.
(a) What does the figure 9 indicate?
(b) What does the figure 4 indicate?
(c) What is the number of protons in atom X?
(d) What is the number of neutrons in atom X?
(e) What is the number of electrons in atom X?
(f) How many electrons are there in the outermost shell of an atom of element X?
(g) Write the symbol of ion formed by an element Z is 2, 8, 8.
(a) The figure 9 indicates mass number.
(b) The figure 4 indicates atomic number.
(c) The number of protons in atom X should be 4.
(d) The number of neutrons in atom X should be 5.
(e) The number of electrons in atom X is 4.
(f) In the outermost shell of an atom of element X there are 2 electrons.
(g) The symbol of ion formed by an element Z is Lithium (Li)
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