Exercise 1

Nitrogen (atomic number 7) and phosphorus (atomic number 15) belong to group 15 of the Periodic Table. Write the electronic configuration of these two elements. Which of these will be more electronegative? Why?

Nitrogen: Atomic number - 7 Electronic configuration - 1s2 2s2 2p3 Nitrogen: Atomic number - 15 Electronic configuration - 1s2 2s2 2p6 3s2 3p3 The number of shell increases in the periodic table...

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An atom has electronic configuration 2, 8, 7. (a) What is the atomic number of this element? (b) To which of the following elements would it be chemically similar? (Atomic numbers are given in parentheses.) N(7), F(9), P(15), Ar(18)

(a)The element is Chlorine (Cl) and the atomic number of chlorine is 17. (b) The atom with the electronic configuration of 2, 8, 7 which is the chlorine is chemically identical to Fluorine (F) which...

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Which element has? (a) Two shells, both of which are completely filled with electrons? (b) The electronic configuration 2, 8, 2? (c) A total of three shells, with four electrons in its valence shell? (d) A total of two shells, with three electrons in its valence shell?(e) twice as many electrons in its second shell as in its first shell?

(a) Neon (Ne) has two shells in which both are completely filled with electrons. (b) Magnesium (Mg) has the electronic configuration 2, 8, 2. (c) Silicon (Si) has a total of three shells, with four...

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Which of the following statements is not a correct statement about the trends when going from left to right across the periods of Periodic Table. (a) The elements become less metallic in nature. (b) The number of valence electrons increases. (c) The atoms lose their electrons more easily. (d) The oxides become more acidic

Correct Answer: (c) The atoms lose their electrons more easily Explanation: Atoms do not lose their electrons easily because as we move from left to right across the periodic table, the non-metallic...

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(a) Lithium, sodium, potassium are all metals that react with water to liberate hydrogen gas. Is there any similarity in the atoms of these elements? (b) Helium is an unreactive gas and neon is a gas of extremely low reactivity. What, if anything, do their atoms have in common?

(a) Lithium, sodium, potassium are the metals that are unstable because of the unfilled outermost shells. This is the reason that they react with water in order to release hydrogen and these metals...

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