High School Chemistry Unit 1

Electrons

Negatively charged subatomic particles orbiting the nucleus.

Neutrons

Neutral subatomic particles found in the nucleus.

Protons

Positively charged particles in the nucleus.

Atomic Number

Number of protons in an atom's nucleus.

Atomic Mass

Total mass of protons and neutrons in an atom.

Isotopes

Atoms of the same element with different numbers of neutrons.

Ions

Charged atoms or molecules.

Cations

Positively charged ions formed by losing electrons.

Anions

Negatively charged ions formed by gaining electrons.

Calculating Ion Charge

Subtract electrons from protons for cations, or protons from electrons for anions.

Radio Waves

Electromagnetic waves with the longest wavelength and lowest frequency, used for AM and FM radio signals.

Microwaves

Electromagnetic waves with higher frequency than radio waves, utilized in microwave ovens for heating food and in WiFi signals.

Infrared Radiation

Electromagnetic waves with higher frequency than microwaves, emitted by objects at everyday temperatures, commonly associated with warmth.

Visible Light

Electromagnetic radiation visible to the human eye, perceived as different colors based on frequency, with the longest wavelength seen as red.

Ultraviolet (UV) Radiation

Electromagnetic radiation beyond visible light, not visible to the human eye, with high enough energy to cause damage to living tissues.

X-rays

Electromagnetic radiation beyond UV, capable of ionizing atoms and used in medical imaging, where dense tissues block more X-rays.

Gamma Rays

Electromagnetic radiation with the highest frequency and energy, produced by high-energy interactions in space and used in radiation therapy.

Valence Electrons

Electrons in the outermost shell of an atom, determining most of its chemical behaviors, can be quickly identified using the periodic table.

Lewis Diagrams

Representations of valence electrons in atoms within a molecule, with each dot or line symbolizing a valence electron.

Atomic Radii Trends

Trends in atomic size on the periodic table, where atomic radius decreases across a period and increases down a group due to nuclear charge and shielding effects.

Ionization Energy

Energy required to remove an electron from a neutral atom, with trends showing an increase across a period and a decrease down a group due to nuclear charge and atomic size.