Joseph Todd Chemistry Chapter 4

s-sublevel

Any orbital can be occupied by a maximum of two electrons, each with its own spin quantum number s. The simple names s orbital, p orbital, d orbital and f orbital refer to orbitals with angular momentum quantum number ℓ = 0, 1, 2 and 3 respectively.

number of neutrons

Atomic Mass - Atomic Number

Rutherford

Ernest Rutherford was British physicist who became known as the father of nuclear physics. In early work he discovered the concept of radioactive half-life, proved that radioactivity involved the nuclear transmutation of one chemical element to another. In 1911, although he could not prove that it was positive or negative, he theorized that atoms have their charge concentrated in a very small nucleus and thereby pioneered the Rutherford model of the atom, through his discovery and interpretation of Rutherford scattering in his gold foil experiment.

Goldstein

Eugen Goldstein was a German physicist. He was an early investigator of discharge tubes, the discoverer of anode rays, and is sometimes credited with the discovery of the proton.

JJ Thompson

In 1897, J.J. Thomson discovered the electron by experimenting with a Crookes, or cathode ray, tube. He demonstrated that cathode rays were negatively charged. In addition, he also studied positively charged particles in neon gas. Thomson realized that the accepted model of an atom did not account for negatively or positively charged particles. Therefore, he proposed a model of the atom which he likened to plum pudding. The negative electrons represented the raisins in the pudding and the dough contained the positive charge. Thomson's model of the atom did explain some of the electrical properties of the atom due to the electrons, but failed to recognize the positive charges in the atom as particles.

Bohr model

In atomic physics, the Rutherford-Bohr model or Bohr model, introduced by Niels Bohr in 1913, depicts the atom as a small, positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus—similar in structure to the solar system, but with attraction provided by electrostatic forces rather than gravity. The mistake in this model is that electrons at the same level had the same spin.

Chadwick

James Chadwick was an English physicist who was awarded the 1935 Nobel Prize in Physics for his discovery of the neutron in 1932.

John Dalton

John Dalton was an English chemist, physicist, and meteorologist. He is best known for his pioneering work in the development of modern atomic theory; and his research into colour blindness, sometimes referred to as Daltonism, in his honour.

Bohr

Niels Henrik David Bohr was a Danish physicist who made foundational contributions to understanding atomic structure and quantum theory, for which he received the Nobel Prize in Physics in 1922.

Gold foil experiment

Rutherford gold foil experiment) were a landmark series of experiments by which scientists discovered that every atom contains a nucleus where its positive charge and most of its mass are concentrated.

Aufbau principle

The Aufbau principle states that electrons orbiting one or more atoms fill the lowest available energy levels before filling higher levels

Pauli exclusion principle

The Pauli exclusion principle is the quantum mechanical principle that states that two identical electrons cannot occupy the same quantum state simultaneously.

Dalton's Atomic Theory

The main points of Dalton's atomic theory were: Elements are made of extremely small particles called atoms. Atoms of a given element are identical in size, mass, and other properties; atoms of different elements differ in size, mass, and other properties. Atoms cannot be subdivided, created, or destroyed. Atoms of different elements combine in simple whole-number ratios to form chemical compounds. In chemical reactions, atoms are combined, separated, or rearranged.

Plum pudding model

The plum pudding model is a scientific model of the atom proposed by J. J. Thomson It was devised shortly after the discovery of the electron but before the discovery of the atomic nucleus. In this model, the atom is composed of electrons surrounded by a soup of positive charge to balance the electrons' negative charges, like negatively charged "plums" surrounded by positively charged "pudding".

shapes of electron orbitals

The shapes of the first five atomic orbitals: 1s, 2s, 2px, 2py, and 2pz.

electron orbital

The term refers to the physical region or space where the electron can be calculated to be present, as defined by the particular mathematical form of the orbital. The repeating periodicity of the blocks of 2, 6, 10, and 14 elements within sections of the periodic table arises naturally from the total number of electrons that occupy a complete set of s, p, d and f atomic orbitals.

number of electrons

same as atomic number unless the atom has gained or lost electrons to become an ion

atomic number

the number of protons in an element

AMU

the unit of mass for atoms (defined by 1/12 the mass of a carbon atom)

atomic mass

the weighted average of the masses of the isotopes of an element