A chemical species that contains 11 protons and 10 electrons can be:
A chemical species that contains 11 protons and 10 electrons can be:
The correct option is D A monoatomic cation
Explanation for correct options:
(C) A polyatomic cation: It is defined as a positively charged ion which is composed of more than one atom. Since the ion formed is having more number of protons than electrons, hence carries a net positive charge. Example; ammonium ion () , it contains 11 protons and 10 electrons.
(D) A monoatomic cation: An ion formed when an atom looses its electron (usually valence electron) with net positive charge which consists of exactly one atom is called as monoatomic cation. Example; sodium ion () . The atomic number of sodium atom is 11, so it contains 11 electrons and 11 protons. But when it looses one valence electron to form an ion the number of electrons and protons now are 10 and 11 respectively.
Explanation for incorrect options:
(A) An atom: It is defined as the smallest constituent of matter that defines the properties of a chemical element. According to Thomson's model of atom “ atom as a whole is electrically neutral” which means that in an atom the number of electrons is equal to the number of protons.
(B) A monoatomic anion: An ion formed when an atom gains an electron and carries net negative charge which consists of exactly one atom is called a monoatomic anion. Example; Fluoride ion () . The atomic number of a fluorine atom is 9, so it contains 9 electrons and 9 protons. But when it gains one electron to form an ion the number of electrons now = 10.
Thus, options (C) and (D) are correct because a chemical species that contains 11 protons and 10 electrons can be either a polyatomic cation or a monoatomic cation.
A monoatomic cation
Explanation for correct options:
(C) A polyatomic cation: It is defined as a positively charged ion which is composed of more than one atom. Since the ion formed is having more number of protons than electrons, hence carries a net positive charge. Example; ammonium ion () , it contains 11 protons and 10 electrons.
(D) A monoatomic cation: An ion formed when an atom looses its electron (usually valence electron) with net positive charge which consists of exactly one atom is called as monoatomic cation. Example; sodium ion () . The atomic number of sodium atom is 11, so it contains 11 electrons and 11 protons. But when it looses one valence electron to form an ion the number of electrons and protons now are 10 and 11 respectively.
Explanation for incorrect options:
(A) An atom: It is defined as the smallest constituent of matter that defines the properties of a chemical element. According to Thomson's model of atom “ atom as a whole is electrically neutral” which means that in an atom the number of electrons is equal to the number of protons.
(B) A monoatomic anion: An ion formed when an atom gains an electron and carries net negative charge which consists of exactly one atom is called a monoatomic anion. Example; Fluoride ion () . The atomic number of a fluorine atom is 9, so it contains 9 electrons and 9 protons. But when it gains one electron to form an ion the number of electrons now = 10.
Thus, options (C) and (D) are correct because a chemical species that contains 11 protons and 10 electrons can be either a polyatomic cation or a monoatomic cation.
