Science Stars Unit 2 Vocabulary

Star

A ball of hot burning gas

Luminosity

The actual brightness of a star (on a scale compared to the brightness of the sun)

HR Diagram

Hertz sprung-Russell diagram, a graph that shows patterns in star properties, such as luminosity and temperature.

Radius

The distance from the center of a circle to any point on circle edge.

Light Diffraction

Occurs when light bends and reveals its parts. Ex) white light bends through a prism and is separated into colors of the spectrum.

Spectroscope

An instrument which spreads light out into its wavelengths, creating a spectrum. Used to view spectra produced by various sources of light.

Telescope

an instrument that uses mirrors to collect electromagnetic radiation from the sky and concentrates it for better observation of bodies in space

Electromagnetic Spectrum

All of the frequencies or wavelengths of electromagnetic radiation (light energy)

Radiation

a type of energy that travels through space as waves

Wavelength

the distance from the peak (top) of one light wave to the peak (top) of the next light wave. Electromagnetic wavelengths vary from the short blips of cosmic rays to the long pulses of radio transmission

Light Spectrum/Spectra

Colored band produced when a beam of light is bent to show its individual wavelengths, such as the colored band produced when white light travels through a prism

ROYGBIV

Colors of the visible spectrum in order of wavelength and frequency.

Emission Spectra

What is produced when a heated gas gives off energy (typically how we see nebula clouds)

Continuous Spectra

Starlight with no interference (ROYGBIV)

Absorption Spectra

What is produced when starlight passing through a cloud of dust/gas

Atom

the basic unit of a chemical element.

Element

A pure substance made up of similar atoms

Protons

a subatomic particle found in the nucleus of every atom. The particle has a positive electrical charge, equal and opposite to that of the electron. The number of protons is the atomic number

Electrons

a negatively charged subatomic particle that can be either bound to an atom or free (not bound).

Neutrons

a subatomic particle found in the nucleus of every atom except that of simple hydrogen. The particle derives its name from the fact that it has no electrical charge; it is neutral.

Nucleus

the positively charged central core of an atom, consisting of protons and neutrons and containing nearly all its mass.

Atomic Number

the number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table.

Periodic Table

a table of the chemical elements arranged in order of atomic number, usually in rows, so that elements with similar atomic structure (and hence similar chemical properties) appear in vertical columns.