New Study Method Flashcards
Newton’s 1st Law
Objects resist change in motion (inertia).
Newton’s 2nd Law
Force = mass x accleration
f=ma
Acceleration happens when a net force is applied.
Newton’s 3rd Law
Equal & opposite forces (action-reaction).
When does Newton’s 2nd Law NOT apply?
At constant speed, acceleration = 0.
Remember:
No acceleration →
No net force →
Newton’s 2nd Law (F = ma) does NOT apply
Why Do Objects Stay in Orbit Instead of Falling into the Sun?
Planets and other objects stay in orbit because of a balance between their speed and the Sun’s gravitational pull.
- If a planet slows down too much, gravity pulls it in, and it spirals toward the Sun.
- If a planet moves too fast, gravity can’t hold it, and it escapes into space.
Why Do Planets Orbit in the Same Direction?
Early planets moved randomly, but gravity & collisions removed unstable ones, leaving only the same-direction orbits.
What process powers a star, and what does it do?
Nuclear Fusion
hydrogen atoms fuse into helium, releasing energy that powers the star.
What happens when a star’s core turns into iron?
When a star’s core turns to iron, it can’t make energy anymore. Gravity pulls everything inward, the core collapses, and the star explodes as a supernova.
What do small stars become after they die?
Small stars shrink into white dwarfs, which slowly cool over time into black dwarfs.
What determines an element’s identity?
The number of protons in an atom’s nucleus. However, the number of neutrons can vary (isotopes), but protons never change.
What are the major trends on the periodic table?
Elements follow patterns based on atomic structure and reactivity.
Left side = Metals (lose electrons easily, good conductors).
Right side = Nonmetals (gain/share electrons, poor conductors).
Noble gases (far right) = Unreactive because they have full valence shells.
Alkali metals (far left) = Super reactive, want to lose 1 electron.
Halogens (second to last column) = Highly reactive, want to gain 1 electron.
How do electron orbitals determine stability?
Electrons fill s, p, and d orbitals in energy levels, impacting reactivity.
s-orbital = Holds 2 electrons.
p-orbital = Holds 6 electrons → Together, s + p = stable octet (8 total).
d-orbital = Holds 10 electrons but doesn’t always need to be full.
How do you write electron configurations?
se the format (shell number) (orbital letter) (electron count) to show how electrons fill orbitals.
Example: Carbon (C) = 1s² 2s² 2p²
s-orbital holds 2, p-orbital holds 6, d-orbital holds 10.
Elements “want” full outer shells (octet rule = 8 valence electrons).
Shortcut: Use noble gas notation (e.g., [Ne] 3s² for Mg).
