Period Trends
Learning Log
This week in Chemistry, the main focus was entirely on Chapter 5, Period Trends. Dmitri Mendeleev created the first periodic table of elements in which elements with similar properties were grouped together. Henry Moseley, an English scientist, published work that led to both the modern definition of atomic number and the recognition that atomic number is the basis for the organization of the periodic table. The periodic law states that the physical and chemical properties of the elements are periodic functions of their atomic numbers. The modern periodic table is an arrangement of the elements in order of their atomic numbers so that the elements with similar properties fall in the same column or group. The noble gases were primarily founded by John William Strutt and Sir William Ramsey, placed the group between the groups now known as Group 17 and Group 1. The lanthanides are the 14 elements with atomic numbers from 58 (cerium) to 71 (lutetium). These elements required many chemists to distinguish these very similar elements. The actinides are the 14 elements with atomic numbers from 90 (thorium) to 103 (lawrencium). The lactinides and actinides are usually set off below the main portion of the periodic table to save space. Periodicity can be observed in any groups of elements in the periodic table, like the noble gases of group 18 and the alkali metals of group 1. Atomic radius may be defined as one-half the distance between the nuclei of identical atoms that are bonded together. The period trends is the trend to smaller atoms across a period is caused by the increasing positive charge of the nucleus. In general, the atomic radii of the main-group elements increase down a group. An ion is an atom or group of bonded atoms that has a positive or negative charge. Any process that results in the formation of an ion is referred to as ionization. The energy required to remove one electron from a neutral atom of an element is the ionization energy. Ionization energy of the main-group elements increase across each period. Among the main group elements, ionization energies generally decrease down the groups. A positive ion is known as a cation and a negative ion is known as an ion. Electronegativity is a measure of the ability of an atom in a chemical compound to attract electrons from another atom in the compound.
Lab Abstract
The lab done this week in Chemistry was related to Chapter 5, Periodic Trends. There were two scatter-plot graphs done showing the ionization energy of one group and the electronegativity of another group. These two graphs showed that there was a period trend that either increased or decreased. Overall, the graphs done showed visually how the ionization energy and the electronegativity increased or decreased depending on the group in the period table.
Learning Log
This week in Chemistry, the main focus was entirely on Chapter 5, Period Trends. Dmitri Mendeleev created the first periodic table of elements in which elements with similar properties were grouped together. Henry Moseley, an English scientist, published work that led to both the modern definition of atomic number and the recognition that atomic number is the basis for the organization of the periodic table. The periodic law states that the physical and chemical properties of the elements are periodic functions of their atomic numbers. The modern periodic table is an arrangement of the elements in order of their atomic numbers so that the elements with similar properties fall in the same column or group. The noble gases were primarily founded by John William Strutt and Sir William Ramsey, placed the group between the groups now known as Group 17 and Group 1. The lanthanides are the 14 elements with atomic numbers from 58 (cerium) to 71 (lutetium). These elements required many chemists to distinguish these very similar elements. The actinides are the 14 elements with atomic numbers from 90 (thorium) to 103 (lawrencium). The lactinides and actinides are usually set off below the main portion of the periodic table to save space. Periodicity can be observed in any groups of elements in the periodic table, like the noble gases of group 18 and the alkali metals of group 1. Atomic radius may be defined as one-half the distance between the nuclei of identical atoms that are bonded together. The period trends is the trend to smaller atoms across a period is caused by the increasing positive charge of the nucleus. In general, the atomic radii of the main-group elements increase down a group. An ion is an atom or group of bonded atoms that has a positive or negative charge. Any process that results in the formation of an ion is referred to as ionization. The energy required to remove one electron from a neutral atom of an element is the ionization energy. Ionization energy of the main-group elements increase across each period. Among the main group elements, ionization energies generally decrease down the groups. A positive ion is known as a cation and a negative ion is known as an ion. Electronegativity is a measure of the ability of an atom in a chemical compound to attract electrons from another atom in the compound.
Lab Abstract
The lab done this week in Chemistry was related to Chapter 5, Periodic Trends. There were two scatter-plot graphs done showing the ionization energy of one group and the electronegativity of another group. These two graphs showed that there was a period trend that either increased or decreased. Overall, the graphs done showed visually how the ionization energy and the electronegativity increased or decreased depending on the group in the period table.