Atomic Structure

The nucleus of an atom contains protons and neutrons. Electrons orbit around the nucleus.

An electron carries a negative charge, which is fundamental to its role in atomic structure and chemical bonding.

Neutrons are neutral particles, meaning they have no electrical charge.

Electrons orbit around the nucleus of an atom in regions called shells or orbitals.

John Dalton is known as the father of atomic theory for proposing that all matter is composed of atoms.

Electrons have the smallest mass among the subatomic particles, approximately 1/1836 of a proton's mass.

Isotopes are atoms of the same element that have different numbers of neutrons, resulting in different mass numbers.

The atomic number represents the number of protons in the nucleus of an atom, which defines the element.

The mass number is the sum of protons and neutrons in the nucleus of an atom.

James Chadwick discovered the neutron in 1932, completing the understanding of atomic structure.

Atoms are the basic building blocks of matter, combining to form molecules and compounds.

Rutherford proposed the nuclear model, where electrons orbit a dense, positively charged nucleus.

An anion is an ion with more electrons than protons, giving it a net negative charge.

A cation is an ion with fewer electrons than protons, resulting in a net positive charge.

The nucleus contains protons and neutrons, which account for nearly all the mass of an atom.

J.J. Thomson discovered the electron in 1897 through experiments with cathode rays.

Isobars are atoms of different elements that have the same mass number but different atomic numbers.

The mass number is the sum of protons and neutrons in the nucleus of an atom.

The number of protons in an atom determines its identity as a specific element.

In a neutral atom, the number of protons equals the number of electrons, balancing the charges.

Neutrons are neutral particles with no electrical charge.

The first electron shell in an atom is called the K shell.

The K shell can hold a maximum of 2 electrons.

The L shell can hold a maximum of 8 electrons.

The Aufbau principle explains how electrons fill atomic orbitals of increasing energy levels.

The outermost shell of an atom is called the valence shell, where valence electrons are located.

Electrons in the outermost shell are called valence electrons and are involved in chemical bonding.

The electrostatic force of attraction between the positively charged nucleus and negatively charged electrons keeps electrons in orbit.

Eugen Goldstein discovered the proton in 1886 through experiments with canal rays.

An atom is electrically neutral because the number of positively charged protons equals the number of negatively charged electrons.

Electrons are involved in chemical bonding, as they interact with electrons from other atoms to form bonds.

Ernest Rutherford discovered the nucleus through the gold foil experiment, revealing a dense, positively charged center.

The mass of an electron is approximately 1/1836 of an atomic mass unit (amu).

A proton carries a positive charge of +1.

The main energy levels in an atom are called shells, where electrons are located.

Niels Bohr proposed a model where electrons move in circular orbits around the nucleus.

Radioisotopes are unstable atoms with extra neutrons, often emitting radiation as they decay.

Electrons move in regions called orbitals, which define their probable locations around the nucleus.

Hydrogen is the first element in the periodic table, with an atomic number of 1.

Atoms combine to form molecules through chemical bonding.

Carbon has an atomic number of 6, meaning it has 6 protons.

Sodium has 11 protons, giving it an atomic number of 11.

Neutrons and protons have similar masses, but neutrons are slightly heavier than protons.

Hydrogen is the lightest element, with an atomic mass of approximately 1 amu.

An alpha particle consists of 2 protons and 2 neutrons, giving it a charge of +2.

Gamma radiation is electromagnetic radiation with no charge or mass.

Beta particles are high-energy electrons emitted during radioactive decay.

Protons are present in both atoms and ions, as they define the element's identity.

Stable atoms typically have a full outer shell of electrons, making them chemically inert.

Metal atoms tend to lose electrons, forming positively charged ions called cations.