chemistry: intro

What are atoms?

Atoms are the basic building blocks of matter, consisting of a nucleus made up of protons and neutrons, surrounded by electrons in orbitals.

What defines an element?

An element is a pure substance that consists of only one type of atom and is listed in the periodic table.

What does the atomic number represent?

The atomic number represents the number of protons in an element's nucleus.

What are compounds?

Compounds are substances formed when two or more elements chemically bond together in fixed proportions.

Give an example of a compound.

Water ($H_2O$) is an example of a compound consisting of hydrogen and oxygen atoms.

What are molecules?

Molecules are formed when two or more atoms bond together, and they can be the same atoms (e.g., $O_2$) or different atoms (e.g., $CO_2$).

What is a chemical bond?

Chemical bonds are the forces that hold atoms together in molecules and compounds.

What is an ionic bond?

Ionic bonds are formed when electrons are transferred from one atom to another, resulting in charged ions that attract each other.

What is a covalent bond?

Covalent bonds are formed when two atoms share electrons.

What are metallic bonds?

Metallic bonds are formed by the attraction between freely-moving electrons and positively charged metal ions.

What is stoichiometry?

Stoichiometry is the calculation of reactants and products in chemical reactions.

What are mass-mole calculations?

Mass-mole calculations allow for the conversion between grams and moles using molar mass to facilitate stoichiometric calculations.

What are isotopes?

Isotopes are variants of a chemical element that have the same number of protons but different numbers of neutrons.

What are stable isotopes?

Stable isotopes do not undergo radioactive decay.

What are radioactive isotopes?

Radioactive isotopes decay over time and can be used in radiometric dating and medical applications.

What is atomic mass?

Atomic mass is the weighted average mass of an element's isotopes based on their natural abundance.

What is the formula for calculating atomic mass?

The formula is: $\text{Atomic Mass} = \frac{\text{(Isotope mass} \times \text{abundance) + …}}{100}$.

What does electronic configuration describe?

Electronic configuration describes the arrangement of electrons in an atom's orbitals.

What is the maximum number of electrons in a shell formula?

The maximum number of electrons in each shell is given by the formula $2n^2$, where $n$ is the shell level.

What is the Aufbau Principle?

The Aufbau Principle states that electrons fill from the lowest energy level to the highest.

What is the Pauli Exclusion Principle?

The Pauli Exclusion Principle states that no two electrons in an atom can have the same set of four quantum numbers.

What is Hund's Rule?

Hund's Rule states that every orbital in a subshell is singly occupied before any orbital is doubly occupied.

What is the electronic configuration for carbon?

The electronic configuration for carbon ($C$) is $1s^2 2s^2 2p^2$.