Atomic Structure and Periodic Table

Study Notes

An atom consists of three main parts: protons, neutrons, and electrons.
Protons: positively charged, found in the nucleus, and determine the element of an atom.
Neutrons: no charge, found in the nucleus, and contribute to the mass of an atom.
Electrons: negatively charged, found in energy levels around the nucleus, and participate in chemical bonding.

A tabular arrangement of elements, organized by atomic number (number of protons) and recurring chemical properties.
Elements are arranged in rows (periods) and columns (groups).
Periods: elements in the same period exhibit similar trends in chemical properties due to the same number of electron shells.
Groups: elements in the same group exhibit similar chemical properties due to the same number of electrons in the outermost energy level.

The process of forming a chemical bond between two or more atoms, resulting in a molecule.
Types of bonds:
- Ionic bond: formed by the transfer of electrons between atoms, resulting in ions with opposite charges.
- Covalent bond: formed by the sharing of electrons between atoms, resulting in a molecule.
- Hydrogen bond: a weak bond between atoms with a hydrogen atom bonded to a highly electronegative atom.

Atoms of the same element with the same number of protons (atomic number) but a different number of neutrons (atomic mass).
Isotopic notation: represented by the symbol of the element, followed by the mass number (total number of protons and neutrons).
Example: carbon-12 (6 protons, 6 neutrons) and carbon-14 (6 protons, 8 neutrons) are isotopes of carbon.

The energy required to remove an electron from an atom in its ground state.
First ionization energy: the energy required to remove the first electron from an atom.
Successive ionization energies: the energy required to remove subsequent electrons from an atom, increasing in energy.
Factors affecting ionization energy:
- Atomic size: smaller atoms have higher ionization energy.
- Nuclear charge: atoms with a higher nuclear charge have higher ionization energy.
- Electron shielding: electrons in inner energy levels shield outer electrons from the nuclear charge, decreasing ionization energy.

An atom consists of three main parts: protons, neutrons, and electrons.
Protons are positively charged and found in the nucleus, determining the element of an atom.
Neutrons have no charge, are found in the nucleus, and contribute to the mass of an atom.
Electrons are negatively charged, found in energy levels around the nucleus, and participate in chemical bonding.

The periodic table is a tabular arrangement of elements, organized by atomic number and recurring chemical properties.
Elements are arranged in rows (periods) and columns (groups).
Periods exhibit similar trends in chemical properties due to the same number of electron shells.
Groups exhibit similar chemical properties due to the same number of electrons in the outermost energy level.

Chemical bonding is the process of forming a bond between two or more atoms, resulting in a molecule.
Types of bonds include:
- Ionic bond: formed by the transfer of electrons between atoms, resulting in ions with opposite charges.
- Covalent bond: formed by the sharing of electrons between atoms, resulting in a molecule.
- Hydrogen bond: a weak bond between atoms with a hydrogen atom bonded to a highly electronegative atom.

Isotopes are atoms of the same element with the same number of protons (atomic number) but a different number of neutrons (atomic mass).
Isotopes are represented by the symbol of the element, followed by the mass number (total number of protons and neutrons).
Example: carbon-12 (6 protons, 6 neutrons) and carbon-14 (6 protons, 8 neutrons) are isotopes of carbon.

Ionization energy is the energy required to remove an electron from an atom in its ground state.
First ionization energy is the energy required to remove the first electron from an atom.
Successive ionization energies increase in energy.
Factors affecting ionization energy include:
- Atomic size: smaller atoms have higher ionization energy.
- Nuclear charge: atoms with a higher nuclear charge have higher ionization energy.
- Electron shielding: electrons in inner energy levels shield outer electrons from the nuclear charge, decreasing ionization energy.