Question

1. complete the following table.

isotope atomic number z mass number a number of electrons
27 59 25
14n
3 7 3
3 6 3
58zn2+
19f-

1. describe what the isotopes of an element have in common and how they are different.
2. what makes an atom? provide an answer in complete sentences that describes the components of an atom and how those components relate to the atomic symbol for the various isotopes of an atom.

problems

1. estimate the mass of one 14c atom (in amu) as precisely as you can (from the data in the model). explain your reasoning.
2. use the data in model 1 to estimate the values (in amu) of:

a) the mass of an electron
b) the mass of a proton
c) the mass of a neutron

1. the mass values calculated in problem 2 are only approximate because when atoms (up through iron) are made (mainly in stars) from protons, neutrons, and electrons, energy is released. einstein’s equation e = mc² enables us to relate the energy released to the mass loss in the formation of atoms. use the known values for the mass of a proton, 1.0073 amu, the mass of a neutron, 1.0087, and the mass of an electron, 5.486×10⁻⁴ amu, to show that the mass of a 12c atom is less than the sum of the masses of the constituent particles.

Explanation:

Step1: Recall atomic - related concepts

The atomic number (Z) is equal to the number of protons and in a neutral atom, the number of electrons. The mass number (A) is the sum of protons and neutrons. For ions, the number of electrons is adjusted according to the charge.

Step2: Analyze the first row

Given Z = 27, A = 59, number of electrons = 25. The element with atomic number 27 is Cobalt (Co). Since there are 25 electrons and 27 protons, it is a Co²⁺ ion.

Step3: Analyze the second row

For \(^{14}N\), the atomic number of nitrogen is Z = 7, mass number A = 14. In a neutral atom, the number of electrons is equal to the atomic number, so number of electrons = 7. The given values of Z = 3, A = 7, number of electrons = 3 are incorrect for \(^{14}N\).

Step4: Analyze the third row

Given Z = 3, A = 6, number of electrons = 3. The element with atomic number 3 is Lithium (Li). This is a neutral Li atom.

Step5: Analyze \(^{58}Zn^{2 +}\)

The atomic number of zinc (Zn) is Z = 30. For \(^{58}Zn^{2+}\), the mass number A = 58. Since it has a + 2 charge, the number of electrons is 30 - 2=28.

Step6: Analyze \(^{19}F^-\)

The atomic number of fluorine (F) is Z = 9. The mass number A = 19. Since it has a - 1 charge, the number of electrons is 9+1 = 10.

Isotope	Atomic Number (Z)	Mass Number (A)	Number of Electrons
\(^{14}N\)	7	14	7
\(^{6}Li\)	3	6	3
\(^{58}Zn^{2+}\)	30	58	28
\(^{19}F^-\)	9	19	10

1. Brief Explanation: Isotopes of an element have the same atomic number (same number of protons), which determines the element's identity. They differ in mass number because they have different numbers of neutrons.

Answer:

**: Isotopes of an element have the same number of protons (and thus the same atomic number), which gives them the same chemical properties. They differ in the number of neutrons, resulting in different mass numbers.

1. Brief Explanation: An atom is made up of protons, neutrons, and electrons. The atomic number (Z) in the atomic symbol represents the number of protons. The mass number (A) represents the sum of protons and neutrons. Isotopes have the same Z - value but different A - values due to different neutron numbers.