Chemistry
This determines the reactivity of an element
valence or number of valence electrons or number of electron's in an element's outermost energy level
change in total distance over change in time
speed
the path a revolving object takes as gravity holds the object in a repeating path
orbit
all of the space, energy, and matter of every kind comprise this
universe or cosmos
local and immediate conditions of climate produce this
weather
The two sub-atomic particles that occur in a stable atomic nucleus
protons and neutrons
Two objects are travelling in straight lines at the same constant speed but there velocoities are different because what is different?
direction
what does earth do that produces periods of day and night every 24 hours?
rotate or rotation
a group of millions of stars, gas, and dust that uniformly move about a central gravitation attractant
galaxy
weathering also produces erosion of rock into fine particles due to these two influences on the earth's surface
wind and flowing water (including rain)
the fundamental particles from which protons and neutrons are formed
quarks
Acceleration occurs with a change in one or both of these?
speed or direction
what causes the earth's seasons?
tilt of the earth's axis of rotation
a star so small and dense that its gravity prevents the escape of light
black hole
the wind belt high in the atmosphere that pushes cold air down to the tropics and warm air up to higher latitudes
jet stream
the number of these determine the elemental identity of an atom
protons
all objects resist change in motion because of their what?
inertia
the partially shaded region of the earth during a solar eclipse
penumbra
diagram plotting a star's tempertaure and brightness
H-R or Hertzsprung Russel
three most general types of plate boundaries
convergent, divergent, transform
the element that is chemically stable although it has a valence of 2 when net charge is zero
He or Helium
a measure of how difficult stopping a moving object is, measured as mass x velocity, is called what?
momentum
type of high tide that occurs when the moon is at a right angle to the line between earth and sun, when high tode is lower than the highest high, and low tide is higher than the lowest low
neap
Stars are acceleration away from us, as demonstrated by red-shifting of the electromagnetic spectra. What universal influence is hypothesized to cause this acceleration?
dark energy
the most violent thunderstorms form because of the approach of what kind of front?
cold front