Chemistry of Life: Nature of Matter and Properties of Water

A set of vocabulary flashcards reviewing subatomic particles, isotopes, radioactive decay, ions, and chemical properties of water.

Atomic Number

The number of protons in an atom of an element.

Isotopes

Atoms of the same element that have a different number of neutrons, giving them a different atomic mass.

Mass Number

The total number of protons and neutrons in an atom.

Average Atomic Mass

The weighted average mass of all naturally occurring isotopes of an element, calculated based on the mass and abundance of each isotope.

Henry Becquerel

The scientist who first noticed that some elements spontaneously give off energy.

Marie Curie

The scientist who defined elements that spontaneously emit radiation as radioactive.

Radioactive

Describing elements that spontaneously emit radiation from their nuclei.

Nuclear Decay

A process that occurs when an unstable nucleus changes into another more stable nucleus by emitting radiation.

Alpha Particle

A particle consisting of 2 protons and 2 neutrons released during alpha decay, which decreases the decaying atom's atomic number by 2.

Alpha Symbol

The Greek letter $\alpha$ used to denote an alpha particle.

Beta Decay

A nuclear decay process in which a neutron changes into a proton and a high-energy electron, increasing the atomic number by 1.

Beta Symbol

The Greek letter $\beta$ used to denote a beta particle.

Gamma Rays

High-energy radiation containing no particles that can be emitted during nuclear decay without changing one element into another.

Gamma Symbol

The Greek letter $\gamma$ used to denote gamma radiation.

Ion

An atom that is no longer neutral because it has either gained or lost electrons.

Cation

A positively charged ion formed when an atom loses electrons.

Anion

A negatively charged ion formed when an atom gains electrons.

Polarity

A characteristic of a molecule whose overall charge is neutral, but has small opposite charges on opposite ends.

Universal Solvent

A term for water, named for its ability to dissolve many different substances due to its polar nature.

Cohesion

The attraction among molecules that are alike, which causes water molecules to stick to each other.

Adhesion

The attraction among molecules that are different, causing water molecules to stick to other substances.

Density

The mass per unit volume of a material.

Solution

A mixture in which the molecules of a substance are evenly spread out.

Solvent

The liquid part of a solution that dissolves the solute.

Solute

The solid substance that is dissolved in a solvent.

Suspension

A mixture in which the molecules of a substance are not evenly distributed, never completely dissolve, and eventually settle to the bottom.

pH Scale

A scale ranging from 0 to 14 that measures the concentration of $H^+$ ions in a solution.

Buffers

Weak acids that react with stronger acids to neutralize them and help maintain stable pH levels in the body.

Homeostasis

The state of stable internal conditions maintained by a living organism.