Atoms, Molecules, and Ions Lecture Notes

These flashcards summarize key concepts from the lecture on atoms, molecules, and ions, including laws of atomic theory, definitions of isotopes, and nomenclature of compounds.

What did Democritus propose about the smallest particle of nature?

He proposed that it was called 'atomos,' meaning uncuttable.

Who organized the principles of atomic theory in the early 1800s?

John Dalton organized the principles of atomic theory.

What is the law of constant composition?

It states that a compound has a definite composition, meaning the relative number of atoms of each element in the compound is the same in any sample.

Who discovered the law of constant composition?

Joseph Proust discovered the law of constant composition.

What does the law of conservation of mass state?

The total mass of substances present at the end of a chemical process is the same as the mass of substances present before the process.

Who discovered the law of conservation of mass?

Antoine Lavoisier discovered the law of conservation of mass.

Define the law of multiple proportions.

If two elements form more than one compound, the masses of one element that combine with a fixed mass of the other element are in the ratio of small whole numbers.

What is an isotope?

Isotopes are atoms of the same element with different masses due to varying numbers of neutrons.

What is the atomic number?

The atomic number is the number of protons in the nucleus of an atom.

What is the significance of atomic weight?

Atomic weight is the average mass of an element's isotopes weighted by their relative abundances.

What are cations?

Cations are positively charged ions formed when atoms lose electrons.

What are anions?

Anions are negatively charged ions formed when atoms gain electrons.

How do you write a formula for ionic compounds?

The charge on the cation becomes the subscript on the anion and vice versa, ensuring the compound is electrically neutral.

What is a polyatomic ion?

A polyatomic ion is a group of atoms that have a net charge due to the loss or gain of electrons.

What does it mean to say an element is diatomic?

It refers to elements that naturally occur as molecules composed of two atoms.

What does the prefix 'hydro-' signify in acid nomenclature?

It indicates that the anion ends in '-ide', and the acid will be named with the prefix 'hydro-' added to the root of the element and '-ic acid' at the end.

What differentiates empirical formulas from molecular formulas?

Empirical formulas give the lowest whole-number ratio of the atoms, while molecular formulas give the exact number of each atom in a molecule.

What is the water of hydration?

Water of hydration refers to water molecules that are associated with ionic compounds in a specific ratio.