1.
A point of infinite density and temperature where the universe began
2.
The leading scientific model explaining that the universe expanded from an extremely hot, dense point
3.
The attractive force that pulls objects with mass together
4.
A fundamental building block of matter that combines to form protons and neutrons
5.
A high-energy state of matter consisting of free electrons and bare atomic nuclei
6.
The nuclear process that created the first atomic nuclei in the early universe
7.
The process where lighter atomic nuclei fuse together under extreme heat and pressure
8.
A massive explosion of a dying star that disperses heavy elements into space
9.
Invisible matter that does not emit light and is only detected through gravity
10.
The region around a star where conditions allow liquid water to exist on a planet's surface
11.
The apparent change in frequency or pitch of a wave due to motion between source and observer
12.
The distance between successive peaks or crests of a wave
13.
The number of wave cycles that pass a given point per second
14.
The stretching of light toward longer wavelengths as an object moves away
15.
The compressing of light toward shorter wavelengths as an object moves closer
16.
The region of the electromagnetic spectrum where leftover Big Bang radiation is detected
17.
An instrument that splits light into its component colors and wavelengths
18.
A pattern of dark bands produced when atoms absorb specific wavelengths of light
19.
A pattern of bright lines emitted by electrons releasing energy
