Ib Chemistry Hl Topic 3

1. Describe the arrangement of elements in the periodic table in order of increasing atomic number.

The periodic table is organized by arranging elements in order of increasing mass number.

The periodic table is arranged solely based on the physical state of elements at room temperature.

Elements are arranged in the periodic table based on their decreasing atomic number from left to right.

Names and symbols of the elements are givenin the Chemistry data booklet. The history of theperiodic table will not be assessed.
Periodic Table is arranged according to increasing atomic number and consists ofhorizontal rows called periods, and vertical columns called groups (or families). Thearrangement is such that elements with similar chemical properties fall directlybeneath each other in the same group.

2. Distinguish between the terms group and period.

A period is a horizontal row in the periodic table while a group is a vertical row.

A period is a series of elements arranged according to increasing atomic number, which begins with the first element having one electron in a new main energy level.
A group is a vertical column consisting of elements with the same electron arrangement in their outer energy levels, which gives the group similar chemical properties.

A group is a series of elements with increasing atomic mass, while a period is a horizontal column.

A group is a series of elements arranged according to increasing atomic number, while a period is a vertical column.

In the periodic table, periods are horizontal rows while groups are vertical columns. Additionally, groups have elements with similar outer electron configurations, whereas periods involve elements arranged by increasing atomic number.

Explanation

In the periodic table, periods are horizontal rows while groups are vertical columns. Additionally, groups have elements with similar outer electron configurations, whereas periods involve elements arranged by increasing atomic number.

3. Apply the relationship between the electron arrangement of elements and their position in the periodic table up to Z = 20.

Valence electrons are electrons in the outermost energy level (the highest energy level)of an atom and are usually the electrons that take part in a chemical reaction. Properties of elements are chiefly due to the number and arrangement of electrons in theouter energy level of atoms.

Electrons are arranged in the nucleus of an atom.

Valence electrons are located in the innermost energy level of an atom.

The number of protons in an atom determines its electron arrangement.

Properties of elements are chiefly due to the number and arrangement of electrons in the outer energy level of atoms.

Explanation

Properties of elements are chiefly due to the number and arrangement of electrons in the outer energy level of atoms.

4. Apply the relationship between the number of electrons in the highest occupied energy level for an element and its position in the periodic table.

The number of valence electrons decreases down a group and increases across a period.

The number of valence electrons decreases both across a period and down a group.

The number of valence electrons increases down a group and decreases across a period.

The number of valence electrons is the same for a group, but increases across a period.

The number of valence electrons determines the chemical properties of an element, and it is consistent within a group but increases as you move from left to right across a period in the periodic table.

Explanation

The number of valence electrons determines the chemical properties of an element, and it is consistent within a group but increases as you move from left to right across a period in the periodic table.

5. Define the terms first ionization energy and electronegativity.

The measure of an element's ability to conduct electricity.

Electronegativity: The tendency for the atoms of the element to attract electrons when they arechemically combined with another element.
Ionisation energy: The energy that is required (or given out) to overcome the attraction of the nuclear charge and remove an electron from a gaseous atom. Removing 1 electron results in a +1 charge.

The ability of an atom to lose electrons when chemically combined with another element.

The energy that is released when an electron is added to an atom in gaseous state.

Electronegativity and first ionization energy are fundamental concepts in chemistry related to the behavior of atoms and their interactions with other elements.

Explanation

Electronegativity and first ionization energy are fundamental concepts in chemistry related to the behavior of atoms and their interactions with other elements.

6. Describe and explain the trends in atomic radii, ionic radii, first ionization energies, electronegativities and melting points for the alkali metals and the halogens.

Electronegativity trends among the halogens are solely determined by atomic mass.

First ionization energies decrease down a group because of increasing effective nuclear charge.

Data for all these properties is listed in the Chemistrydata booklet. Explanations for the first four trendsshould be given in terms of the balance betweenthe attraction of the nucleus for the electrons andthe repulsion between electrons. Explanationsbased on effective nuclear charge are not required.

The trends in atomic and ionic radii are solely dependent on the number of protons in an atom.

The correct answer focuses on the interplay between nucleus-electron attraction and electron-electron repulsion to explain the trends in atomic radii, ionic radii, first ionization energies, and electronegativities. The incorrect answers either oversimplify the factors at play or provide incorrect explanations based on effective nuclear charge and atomic mass.

Explanation

The correct answer focuses on the interplay between nucleus-electron attraction and electron-electron repulsion to explain the trends in atomic radii, ionic radii, first ionization energies, and electronegativities. The incorrect answers either oversimplify the factors at play or provide incorrect explanations based on effective nuclear charge and atomic mass.

7. Describe and explain the trends in atomic radii, ionic radii, first ionization energies and electronegativities for elements across period 3.

B) Atomic radii increase, ionic radii decrease, first ionization energies decrease, and electronegativities increase.

A) Atomic radii decrease, ionic radii increase, first ionization energies increase, and electronegativities decrease.

See image.

C) Atomic radii decrease, ionic radii decrease, first ionization energies increase, and electronegativities increase.

The trends in atomic radii, ionic radii, first ionization energies, and electronegativities across period 3 are important concepts in understanding the periodic trends of elements.

Explanation

The trends in atomic radii, ionic radii, first ionization energies, and electronegativities across period 3 are important concepts in understanding the periodic trends of elements.

8. Compare the relative electronegativity values of two or more elements based on their positions in the periodic table.

Analyze

Evaluate

Compare.

Contrast

9. Discuss the changes in nature, from ionic to covalent and from basic to acidic, of the oxides across period 3.

Describe the physical properties of the oxides across period 3.

Equations are required for the reactions of Na2O,MgO, P4O10 and SO3 with water.

Explain the atomic structure of the elements across period 3.

Compare the melting points of the oxides across period 3.

The correct answer focuses on the specific reactions of oxides with water, while the incorrect answers touch on unrelated topics.

Explanation

The correct answer focuses on the specific reactions of oxides with water, while the incorrect answers touch on unrelated topics.