Atomic Theory and Structure

These flashcards cover key concepts related to atomic theory, the structure of matter, and significant scientific contributions, aiding in the understanding of atomic structure and its implications.

What is the generalization about the nature of matter?

Matter is electrical in nature.

Who was the first to theorize that matter is made of indivisible particles?

Democritus.

What were the particles called that Democritus theorized?

Atomos, now known as atoms.

What does Dalton's Atomic Theory state about atoms of a particular element?

They are alike in size, mass, and structure.

What is the Law of Conservation of Mass?

It states that the mass of substances remains unchanged in an ordinary chemical reaction; no new atoms are created or destroyed.

What does the Law of Definite Proportions state?

A given compound always has the same fixed proportion of its constituent elements.

What are elemental molecules?

Molecules that consist of the same type of atoms, e.g., H₂, N₂.

What are isotopes?

Atoms of the same element that have the same atomic number but different atomic masses.

What charge does an electron carry?

A negative charge (-1).

Who discovered the proton?

Ernest Rutherford.

What is the relative mass of a proton?

1 amu (atomic mass unit).

What discovery did James Chadwick make?

The neutron.

What is the mass of a neutron?

Approximately 1 amu.

What defines the atomic mass of an atom?

The total number of protons and neutrons in its nucleus.

How is the atomic number defined?

The number of protons in an atom.

What does the emission spectrum represent for an element?

The unique spectrum of colors emitted when its gaseous atoms are heated.

What happens to light when it passes through a prism?

It separates into its component colors, forming a continuous spectrum.

What is the significance of discrete colors in atomic spectra?

They correspond to specific energies emitted by the atoms.

How is the average atomic mass calculated for an element?

By multiplying the atomic mass of each isotope by its abundance.