chem test sg

What does light behave as?

Wave + particle

Longer wavelength means __________ energy.

LESS

Higher frequency means __________ energy.

MORE

When wavelength goes UP, frequency goes __________.

DOWN

Order of EM spectrum from LOW to HIGH energy?

Radio → Micro → IR → Visible → UV → X-ray → Gamma

Order of visible colors from LOW to HIGH energy?

Red → Orange → Yellow → Green → Blue → Indigo → Violet

What happens when an electron jumps UP a level?

ABSORBS energy

What happens when an electron falls DOWN a level?

EMITS energy

When do you see colored light?

When an electron emits visible light

What does a continuous spectrum look like?

An unbroken rainbow

What does a bright-line spectrum look like?

Separate colored lines

Why does each element have unique spectral lines?

Different electron energy levels

According to Planck, energy comes in __________.

Packets called quanta

Why can violet light eject electrons but red may not?

Violet photons have more energy

What did Bohr say about electrons?

They occupy fixed energy levels

What is Heisenberg's Uncertainty Principle?

Can't know exact position AND momentum

In the Bohr model, what does the atomic number represent?

Protons

In the Bohr model, how do you calculate neutrons?

Mass number − atomic number

What is the number of electrons in a neutral atom?

Equal to the atomic number

What are the electron configurations for the first 3 Bohr shells (first 20 elements)?

2, 8, 8

What is the equation for the speed of light?

c = λν

How do you find wavelength from frequency?

λ = c / ν

How do you find frequency from wavelength?

ν = c / λ

How do you find energy from frequency?

E = hν

How do you find energy from wavelength?

E = hc / λ

How do you convert nm to meters?

Multiply by 10⁻⁹

What are the values for c and h?

c = 3.00 × 10⁸ m/s; h = 6.626 × 10⁻³⁴ J·s

What does electron configuration tell you?

Where the electrons go

What does the big number in 3p represent?

Principal energy level

What does the superscript in 3p⁴ indicate?

Number of electrons

How do you write a FULL configuration?

Fill in order until total electrons are added

What is the maximum number of electrons in ONE orbital?

2

What are the max electrons in s, p, d, f sublevels?

2, 6, 10, 14

How many orbitals are in s, p, d, f?

1, 3, 5, 7

What is the filling order through 4p?

1s → 2s → 2p → 3s → 3p → 4s → 3d → 4p

What is the Aufbau principle?

Lowest energy fills first

What is Hund's rule?

SPREAD before pairing

What is the Pauli exclusion principle?

Paired arrows point opposite ways

What do the arrows in a correct p⁴ orbital look like?

[↑↓][↑][↑]

How do you write noble gas shorthand?

Previous noble gas + remaining sublevels

What are the electron counts for noble gases?

He 2, Ne 10, Ar 18, Kr 36, Xe 54

How do you find valence electrons?

Add electrons with highest shell number

How do you identify an element from a configuration?

Add superscripts to get atomic number

What happens to a positive ion (+)?

LOSES electrons

What happens to a negative ion (−)?

GAINS electrons

For Fe²⁺, which electrons leave first?

4s² → leaves [Ar] 3d⁶

Isoelectronic means __________.

Same electrons and configuration

For d-block elements, how do you determine the energy level number?

Period number − 1

Which fills first: 4s or 3d?

4s

What is the difference between ONE f orbital and ENTIRE f sublevel?

2 vs. 14 electrons

What are the shapes of s, p, and most d orbitals?

Sphere, dumbbell, clover