Chemistry Chapter on Radioactivity and Groups

A constant representing the number of particles (atoms, molecules, ions, etc.) in one mole of any substance. It's approximately 6.022 x 10^23.

The number of atoms in exactly 12 grams of carbon-12.

The volume occupied by one mole of a substance.

The volume occupied by a single atom within a crystal lattice.

A crystalline form of pure carbon.

The mass of one mole of a substance.

A measure of how much mass is packed into a given volume.

The distance between the starting and ending points of a particle's movement.

Positively charged particles emitted from radioactive decay, later identified as helium nuclei.

A stream of electrons identical to those found in cathode rays.

Electromagnetic radiation with no mass, emitted from radioactive decay.

The phenomenon where the nucleus of an unstable atom spontaneously changes, emitting particles and energy.

The experiment where a beam of α particles was directed at a thin gold foil, revealing the structure of the atom.

Experiments that revealed the nature of α, β, and γ rays, contributing to our understanding of nuclear structure.

The central, positively charged part of an atom, containing protons and neutrons.

The force that keeps the positively charged protons together in the nucleus, despite their mutual repulsion.

J.J. Thomson's model of the atom that likened it to a plum pudding, with negatively charged electrons (plums) embedded in a sphere of positive charge (pudding).

A beam of electrons that travel from the cathode (negative electrode) towards the anode (positive electrode) in a vacuum tube.

The ratio of the mass of a particle to its charge. It's a fundamental property of charged particles that allows us to understand their behavior in electric and magnetic fields.

The discovery that cathode rays are composed of fundamental particles, later named electrons, that are present in all atoms. This finding revolutionized our understanding of the atom's structure.

The positive charge that was hypothesized by Thomson to be distributed throughout the atom like a pudding, with electrons embedded in it.

The scattering of alpha particles by a thin gold foil, which led to the discovery of the atomic nucleus.

The idea that atoms are made up of smaller, subatomic particles.

A relationship showing the atomic number as the square root of the re-emitted X-ray frequency. This relationship is known as Moseley 's law, and it plays a crucial role in determining the atomic number of an element.

The positive charge of the atomic nucleus, represented by the number of protons it contains.

A subatomic particle found in the nucleus, carrying a positive charge equal in magnitude to the electron's negative charge.

The simplest element, containing only one proton and one electron. It's the building block of all other elements.

A measure of the total number of nucleons (protons and neutrons) in an atom's nucleus.

The number of protons in an atom's nucleus. It defines the chemical element.

A logarithmic scale on both axes used to visualize the relationship between atomic weight and atomic number.

A graphical representation of data points plotted on a graph, often used to visualize trends and relationships.

The International Union of Pure and Applied Chemistry (IUPAC) recommends a system for labeling groups in the periodic table from 1 to 18. Each group contains elements with similar chemical properties.

The alkali metals, including lithium (Li), sodium (Na), and potassium (K), are found in group 1 of the periodic table.

Chalcogens or the oxygen family, including oxygen (O), sulfur (S), and selenium (Se), are in group 16 of the periodic table.

Noble gases, including helium (He), neon (Ne), and argon (Ar), are in group 18 of the periodic table.

The older IUPAC convention used Roman numerals to label groups from IA to VIIIA, with some exceptions for groups 8, 9, and 10.

The pnictogens or nitrogen family, containing nitrogen (N), phosphorus (P), and arsenic (As), are referred to as group 5.

The fluorine family, also known as halogens, includes fluorine (F), chlorine (Cl), and bromine (Br) and are found in group 7.

The IUPAC system is preferred for its simplicity and clarity in representing the periodic table and group relationships.

Waves that are confined to a specific space, resulting in fixed nodes and antinodes. They oscillate in time but don't propagate in space.

The lowest possible frequency of vibration for a standing wave. It's the fundamental tone or the first harmonic.

The points in a standing wave where the amplitude is always zero, meaning no displacement occurs.

The points in a standing wave where the amplitude is maximum, meaning maximum displacement occurs.

The condition where the length of a pipe or string must be an integer multiple of half the wavelength of the wave to sustain a standing wave.

The phenomenon where the frequency of a standing wave within a space is restricted to specific values determined by the boundary conditions. It creates a discrete spectrum.

The relationship between the length of a pipe or string and the wavelengths of standing waves it can sustain, where longer pipes can sustain longer wavelengths and therefore lower frequencies.

A type of wave that is comprised of oscillating electric and magnetic fields. Light is an example of this type of wave.