Question

how many electrons in the ion pb3+ with 82 protons. 79 85 82 161 an atom of an element has 4 protons, 5 neutrons and 2 electrons. which of the following best describes this atom: a neutral atom of helium a isotope of beryllium an ion of beryllium which description best fits the following model:

Explanation:

Step1: Determine the number of electrons in a neutral atom

In a neutral atom, the number of electrons is equal to the number of protons. So, a neutral atom of Pb (lead) with 82 protons has 82 electrons.

Step2: Calculate the number of electrons in the ion

The ion \(Pb^{3 +}\) has a charge of \(+ 3\). A positive charge means the atom has lost electrons. The formula to find the number of electrons in an ion is \(n_{e}=n_{p}-|charge|\). Here, \(n_{p} = 82\) (number of protons) and \(|charge|=3\). So, \(n_{e}=82 - 3=79\).

For the second question:

Step1: Identify the element

The number of protons determines the element. Since there are 4 protons, the element is beryllium (Be, atomic number \(Z = 4\)).

Step2: Analyze the charge

In a neutral atom, the number of electrons is equal to the number of protons. Here, there are 4 protons and 2 electrons. The charge of the atom is \(q=n_{p}-n_{e}=4 - 2=+ 2\). An atom with a non - zero charge is an ion. Isotopes have the same number of protons but different numbers of neutrons. Since the charge is non - zero, it is not a neutral atom or an isotope (in terms of the basic definition for this context, as isotopes are neutral species with same \(Z\) and different \(N\)).

Answer:

For the first question: 79.
For the second question: An ion of beryllium.