Question

1. which is true of the ^{243}am^{3+} ion?

protons electrons neutrons
(a) 148 148 243
(b) 95 98 243
(c) 95 95 148
(d) 95 92 148
use the mass spectroscopy data below for question 18.

1. the figure above represents the mass spectrometry data for an unknown element. which statement best interprets the data below?

(a) there is only one isotope for the unknown element with a mass of 19 amu. this means the isotope has 10 neutrons.
(b) there is only one isotope for the unknown element with a mass of 19 amu. this means the isotope has 9 neutrons.
(c) there is only one ion for the unknown element with a charge of 19 amu. this means the ion has 10 electrons.
(d) there is only one ion for the unknown element with a charge of 19 amu. this means the ion has 9 electrons.

Explanation:

Step1: Determine protons for \(^{243}\text{Am}^{3 +}\)

The atomic number of Americium (\(\text{Am}\)) is \(95\). Protons = atomic number. So protons \(= 95\).

Step2: Calculate electrons for \(^{243}\text{Am}^{3 +}\)

For a cation \(M^{n+}\), electrons \(=\) protons\(-n\). Here \(n = 3\), so electrons \(=95 - 3=92\).

Step3: Calculate neutrons for \(^{243}\text{Am}^{3 +}\)

Mass number \(A=243\). Neutrons \(=A-\) protons. So neutrons \(=243 - 95=148\).

for question 18:

• Mass spectrometry data with a single peak at \(19\) amu implies only one isotope (not ion, as mass is related to isotope mass).
• For an atom, mass number \(A=\) protons + neutrons. If \(A = 19\) and assuming it's a neutral atom (isotope), and if it's \(^{19}\text{F}\) (for example, which is common), protons \(=9\) (atomic number of \(F\)), then neutrons \(=19 - 9=10\).

Answer:

D. 95 protons, 92 electrons, 148 neutrons.