Regents Chemistry Test Preparation Practice Valence Electrons

Which atom in the ground state has an outer- most electron with the most energy?*

(1) Cs

(2) K

(3) Li

(4) Na

The valence electron of which atom in the ground state has the greatest amount of energy?*

(1) cesium

(2) lithium

(3) rubidium

(4) sodium

Compared to the energy and charge of the electrons in the first shell of a Be atom, the electrons in the second shell of this atom have*

(1) less energy and the same charge

(2) less energy and a different charge

(3) more energy and the same charge

(4) more energy and a different charge

Compared to the energy of an electron in the second shell of an atom of sulfur, the energy of an electron in the*

(1) ﬁrst shell is lower

(2) ﬁrst shell is the same

(3) third shell is lower

(4) third shell is the same

Which electron shell in an atom of calcium in the ground state has an electron with the greatest amount of energy?*

(1) 1

(2) 2

(3) 3

(4) 4

Which change in electron location in an atom of calcium is accompanied by the greatest amount of energy emitted?*

(1) from shell 1 to shell 2

(2) from shell 2 to shell 1

(3) from shell 1 to shell 4

(4) from shell 4 to shell 1

In the ground state, which shell of a potassium atom has an electron with the greatest amount of energy?*

(1) first

(2) second

(3) third

(4) fourth

Compare the energy of an electron in the first shell of a cadmium atom to the energy of an electron in the third shell of the same atom.*

Base your answers to questions 9 on the information below and on your knowledge of chemistry.

The Bohr model of the atom was developed in the early part of the twentieth century. A diagram of the Bohr model for one atom, in the ground state, of a specific element is shown below. The nucleus of this atom contains 4 protons and 5 neutrons.

periodic-table, identification-of-element fig: chem62015-exam_g13.png

Using the Bohr model, describe the changes in electron energy and electron location when an atom changes from the ground state to an excited state.*

Base your answers to questions 10 on the information below and on your knowledge of chemistry.

The table below shows data for three isotopes of the same element.

periodic-table, identification-of-element, atomic-concepts, isotopes-atomic-mass fig: chem82018-exam_g8.png

Compare the energy of an electron in the first electron shell to the energy of an electron in the second electron shell in an atom of isotope E.*

Base your answers to questions 11 on the information below and on your knowledge of chemistry.

The two naturally occuring isotopes of lithium are Li-6 and Li-7. The table below shows the atomic mass and percent natural abundance for these isotopes.

atomic-concepts, atomic-structore, proton-neutron-electron fig: chem62022-exam_g8.png

Compare the energy of an electron in the first shell of a lithium atom to the energy of an electron in the second shell of the same atom. [1]*

Base your answers to questions 12 on the information below and on your knowledge of chemistry.

The four naturally occurring isotopes of sulfur are S-32, S-33, S-34, and S-36. The table below shows the atomic mass and percent natural abundance for these isotopes.

periodic-table, identification-of-element fig: chem12020-exam_g9.png

Compare the energy of an electron in the third shell of a sulfur atom to the energy of an electron in the first shell of the same atom. [1]*

Base your answers to questions 13 on the information below and on your knowledge of chemistry.

The element technetium, Tc, has several isotopes. The bright-line spectrum of technetium has been observed in the spectra of some stars.

Compare the energy of an electron in the first shell of a technetium atom to the energy of an electron in the third shell of the same atom. [1]*

Base your answers to questions 14 on the information below.

Iron has been used for thousands of years. In the air, iron corrodes. One reaction for the corrosion of iron is represented by the balanced equation below.

Equation 1: 4Fe(s) + 3O₂(g) → 2Fe₂O₃(s)

In the presence of water, iron corrodes more quickly. This corrosion is represented by the unbalanced equation below.

Equation 2: Fe(s) + O₂(g) + H₂O(ℓ) → Fe(OH)₂(s)

Using equation 1, describe one chemical property of iron.*

Base your answers to questions 15 on the information below and on your knowledge of chemistry.

The diagram below represents three elements in Group 13 and three elements in Period 3 and their relative positions on the Periodic Table.

atomic-concepts, valence-electrons, chemical-bonding, electron-dot-diagrams-(lewis-structures), periodic-table, identification-of-element, chemical-bonding, bonding-tendency-of-elements fig: chem12014-exam_g8.png

Some elements in the solid phase exist in different forms that vary in their physical properties. For example, at room temperature, red phosphorus has a density of 2.16 g/cm³ and white phosphorus has a density of 1.823 g/cm³.

Identify the element from the diagram that will react with chlorine to form a compound with the general formula XCl₄.*