Question Video: Finding the Number of Electrons Lost or Gained by an Atom | Nagwa Question Video: Finding the Number of Electrons Lost or Gained by an Atom | Nagwa

# Question Video: Finding the Number of Electrons Lost or Gained by an Atom Science • First Year of Preparatory School

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An ion has the symbol notation Be²⁺. How many electrons have been lost or gained to form this ion? [A] 2 lost [B] 2 gained [C] 1 lost [D] 1 gained

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### Video Transcript

An ion has the symbol notation Be2+. How many electrons have been lost or gained to form this ion? (A) Two lost, (B) two gained, (C) one lost, (D) one gained.

Atoms are neutrally charged particles that have an equal number of negatively charged electrons and positively charged protons. Ions, however, are charged particles with an unequal number of electrons and protons. Atoms can become ions by gaining or losing electrons. If an atom gains an electron, then the number of negatively charged electrons will be greater than the number of positively charged protons. The species will be negatively charged overall and is called a negative ion. If an atom loses an electron, then the number of negatively charged electrons will be less than the number of positively charged protons. The species will be positively charged overall and is called a positive ion.

In symbol notation, the charge of the ion is written as a superscript to the right of the element symbol. As the given symbol notation shows a positive charge, we know that this is a positive ion and that electrons have been lost to form it. Each electron has a single negative charge, and each proton has a single positive charge. So in order for an ion to have a charge of positive two, a neutral atom must have lost two negatively charged electrons.

Therefore, the number of electrons that have been lost or gained to form the Be2+ ion is answer choice (A), two lost.

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