An atom of element E contains 3 protons, 3 electrons and 4 neutrons:
(a) What is its atomic number?
(b) What is its mass number?
(c) Write the electronic configuration of the element E.
(d) State whether element E is a metal or non-metal. Why?
(e) What type of ion, cation or anion, will be formed by an atom of element E? Why?
(f) Write the symbol of the ion formed by an atom of element E.
(g) What could element X be?
(a) The atomic number of element E is 3.
(b) Element E’s mass number is 7.
(c) The electronic configuration of the element E is 2, 1.
(d) As element E has 1 valence in its outer most shell, so metal. As it shows the tendency to give electron to attain the noble gas configuration.
(e) Cation will be formed by an atom of element E because it has 1 electron in the outer most orbit, which it can lose quickly to form a positively charged ion.
(f) The symbol of the ion formed by an atom of element E is E+.
(g) Element E could be Lithium.