chapter 11 Chapter 11: Energy and Light, Electromagnetic Waves, Bohr Model, Quantum Theory, Electron Configurations, and Periodic Trends

Energy

Ability to do work

Electromagnetic radiation

Energy that travels through space as waves

Wavelength

Distance between two matching points on a wave

Frequency

Number of waves passing a point each second

Amplitude

Height of a wave from the middle

Crest

Highest point of a wave

Trough

Lowest point of a wave

Wave speed formula

c = wavelength × frequency

Speed of light

3.00 × 10⁸ m/s

Photon

A packet of electromagnetic energy

Electromagnetic spectrum

All types of electromagnetic waves

Radio waves

Waves with the longest wavelength and lowest frequency

Gamma rays

Waves with the shortest wavelength and highest frequency

Visible light

Part of the spectrum humans see

Absorption

When an atom takes in energy

Emission

When an atom releases energy

Continuous spectrum

Spectrum showing all colors without gaps

Emission spectrum

Bright colored lines on a dark background

Absorption spectrum

Dark lines missing from a continuous spectrum

Ground state

Lowest energy state of an atom

Excited state

State when an electron moves to a higher energy level

Quantized energy

Energy that exists only in specific amounts

Bohr model

Model showing electrons in specific energy levels

Bohr model energy increase

Electron absorbs energy and moves to a higher level

Bohr model energy decrease

Electron releases energy and moves to a lower level

Quantum model

Model showing where electrons are likely to be found

Orbital

Region where an electron is likely to be found

s sublevel

1 orbital and 2 electrons maximum

p sublevel

3 orbitals and 6 electrons maximum

d sublevel

5 orbitals and 10 electrons maximum

f sublevel

7 orbitals and 14 electrons maximum

Aufbau principle

Electrons fill lower-energy orbitals first

Pauli exclusion principle

Each orbital holds up to 2 electrons with opposite spins

Hund's rule

Electrons fill equal-energy orbitals singly before pairing

Electron configuration

Arrangement of electrons in an atom

Orbital filling order

1s 2s 2p 3s 3p 4s 3d 4p 5s

Maximum electrons in s

2 electrons

Maximum electrons in p

6 electrons

Maximum electrons in d

10 electrons

Maximum electrons in f

14 electrons

Valence electrons

Electrons in the outermost occupied energy level

Core electrons

Electrons in inner energy levels

Atomic radius

Size of an atom

Atomic radius trend

Increases down and to the left

Ionization energy

Energy needed to remove an electron from an atom

Ionization energy trend

Increases up and to the right

Metal reactivity trend

Increases down Group 1

Nonmetal reactivity trend

Increases up Group 17

Most reactive nonmetal

Fluorine

4s and 3d filling order

4s fills before 3