Atoms and the Periodic Table

This set of flashcards covers key vocabulary and concepts related to atoms, the periodic table, and chemical principles as outlined in the lecture notes.

Chemical Symbol

A notation of one or two letters representing an element, such as 'C' for carbon.

Avogadro's Number

6.022 × 10²³, the number of atoms or molecules in one mole of a substance.

Cation

A positively charged ion, formed by losing one or more electrons.

Anion

A negatively charged ion, formed by gaining one or more electrons.

Isotope

Atoms of the same element that have different numbers of neutrons.

Atomic Number (Z)

The number of protons in the nucleus of an atom, which determines the element's identity.

Mass Number (A)

The total number of protons and neutrons in the nucleus of an atom.

Dalton's Atomic Theory

The theory stating that matter is made of indivisible atoms, each with a specific mass.

Law of Conservation of Mass

The principle stating that mass cannot be created or destroyed in a chemical reaction.

Mole

A unit for counting particles, defined as 6.022 × 10²³ units.

Periodic Table

A tabular arrangement of elements organized by increasing atomic number and grouped by similar properties.

Subatomic Particles

Particles that make up an atom: protons, neutrons, and electrons.

Nucleus

The central part of an atom containing protons and neutrons.

Proton

A positively charged subatomic particle found in the nucleus of an atom.

Neutron

A neutral subatomic particle found in the nucleus of an atom.

Electron

A negatively charged subatomic particle that occupies the space outside the nucleus.

Law of Definite Proportions

The principle that a compound contains the same proportion of elements by mass, regardless of sample size.

Law of Multiple Proportions

The principle stating that when two elements form multiple compounds, the ratios of the masses of one element that combines with a fixed mass of the other are whole numbers.