Question

A 2- ion has 36 electrons and 45 neutrons. what is its correct symbol

Answer 1

The correct symbol for an ion with 36 electrons, 45 neutrons, and a 2- charge is ^{79}Se^{2-}, representing the element Selenium with a mass number of 79.

Step-by-step explanation:

To find the correct symbol of an ion with 36 electrons, 45 neutrons, and a 2- charge, we first need to determine its atomic number. Since the ion has 2 more electrons than protons (because of its 2- charge), and given it has 36 electrons, the atomic number must be 36 - 2 = 34, which corresponds to the element Selenium (Se). The mass number is the sum of protons and neutrons, so in this case, it is 34 (protons) + 45 (neutrons) = 79. Therefore, the correct symbol for this ion is ^{79}Se^{2-}.

Answer 2

Total electron element having = 36

In order to find number of Protons we will subtract 2 from 36 because 2 electrons are extra with respect to protons, So number of protons are,

# of protons = 36 - 2 = 34

Means, this element has atomic number 34 and electronic configuration of this element is,

1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁴

Now, Valence Shell = 4 = Element is present in Period 4

Valence Electrons = 6 = Element is present in Group 6

Result;
This element is Selenium, with atomic number 34 and atomic mass 79 (# of protons + # of neutrons). And the correct symbol is,

⁷⁹₃₄Se⁻²