Chapter 2 Flashcards by Amelia D

What is light?
A. A wave
B. A particle
C. Both
D. Neither

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_______ is the height of peaks (________).

Amplitude, intensity

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λ = wavelength (m), wavelength is …

The distance between two identical points

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ν = frequency (Hz = s^-1), frequency is …

The number of wavelengths per second

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Wavelength and frequency are related by _________: c = λ × v

The speed of light

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_______ = c = 3.00 × 10^8 m s^-1

Speed of light

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________ – increases as frequency increases (and wavelength decreases).

Energy of light

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Let’s say we have 2 objects 1 m apart (10^0 m). How far apart would 2 objects be that were 10^1 m apart?
A. 1 m
B. 10 m
C. 20 m
D. 100 m
E. 1000 m

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Let’s say we have 2 objects 1 m apart (10^0 m). How far apart would 2 objects be that were 10^2 m apart?
A. 1 m
B. 10 m
C. 20 m
D. 100 m
E. 1000 m

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Let’s say we have 2 objects 1 m apart (10^0 m). How far apart would 2 objects be that were 10^3 m apart?
A. 1 m
B. 10 m
C. 20 m
D. 100 m
E. 1000 m

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Which e/m radiation has wavelengths on the order of the sizes of atoms?
A. Radiowaves (λ ≈ m)
B. Microwaves (λ ≈ cm)
C. X-rays (λ ≈ nm)
D. Gamma rays (λ ≈ pm)

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Determine the wavelength of an X-ray with a frequency of 3.0 × 10^18 Hz in meters. (c = 3.0 × 10^8 m/s).
A. 1.0 × 10^–10 m
B. 9.0 × 10^26 m
C. 9.0 × 10^–19 m
D. 1.0 × 10^–1 m

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Which has the longest wavelength?
A. X-rays
B. Visible
C. Infrared

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Which has the highest frequency?
A. X-rays
B. Visible
C. Infrared

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Which has the highest energy?
A. X-rays
B. Visible
C. Infrared

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Many metals emit _________ when electromagnetic radiation shines on the surface.

Electrons

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When you increase the intensity of UV light …
A. The number of electrons emitted increases
B. The number of electrons emitted decreases
C. There’s no change
D. There’s zero electrons are emitted

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When you keep the intensity the same and increase the wavelength (decreasing the frequency) to the blue …
A. The number of electrons emitted increases
B. The number of electrons emitted decreases
C. There’s no change
D. There’s zero electrons are emitted

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When you keep the intensity the same and increase the wavelength (decreasing the frequency) into the yellow …
A. The number of electrons emitted increases
B. The number of electrons emitted decreases
C. There’s no change
D. There’s zero electrons are emitted

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When you keep the yellow light and increase the intensity …
A. The number of electrons emitted increases
B. The number of electrons emitted decreases
C. There’s no change
D. There’s zero electrons are emitted

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If the frequency of the light is above the threshold frequency, _________ from the metal.

Electrons are emitted

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If the frequency of the light is below the threshold frequency, _________.

No electrons are emitted

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Einstein postulated that light must come in packets of energy (or particles or quanta) – called …

Photons

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The energy of light depends on the __________, not on the intensity.

Frequency

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E/m radiation is a ______ - ______ effect.

Particle, photoelectric

Each photon has a definable energy (______).

E = hν

If the photon has enough energy, it can eject _______.

One electron

What is the energy of a photon of frequency 4.0 × 1018 s–1 (in the X-ray part of the spectrum)? Constant: h = 6.626 × 10–34 J s A. 2.6 × 108 J B. 2.6 × 10–15 J C. 1.7 × 10–52 J D. 6.0 × 1051 J

What is the wavelength of a photon with an energy of 6.2 × 10^–8 J? Constants: c = 3.0 × 10^8 m/s, h = 6.626 × 10–34 J s A. 3.2 × 10^–34 m B. 3.2 × 10^18 m C. 3.2 × 10^–18 m D. 9.4 × 10^25 m

C. SLIDE 40

A covalent bond between two H atoms (in H2) requires 7.2 × 10^–19 J of energy to break, causing the molecule to fall apart. What frequency of light does this correspond to? Constants: c = 3.0 × 10^8 m/s, h = 6.626 × 10^–34 J s A. 1.1 × 10^15 s–1 B. 9.2 × 10^–16 s–1 C. 4.8 × 10^–52 s–1

A. SLIDE 41

A covalent bond between two H atoms (in H2) requires 7.2 × 10^–19 J of energy to break, causing the molecule to fall apart. What is the wavelength? Constants: c = 3.0 × 10^8 m/s, h = 6.626 × 10^–34 J s A. 3.6 × 10^6 m B. 3.3 × 10^23 m C. 2.8 × 10^–7 m

C. SLIDE 42

A covalent bond between two H atoms (in H2) requires 7.2 × 10–19 J of energy to break, causing the molecule to fall apart. What is the wavelength in nm? A. 280 nm B. 2.8 × 10 –16 nm C. 2.8 × 10 –7 nm

A. SLIDE 42

________ is important at very small scales.

Wave-particle duality

The ________ is the same whether that element is on Earth, in the Sun, or in a galaxy light years away.

Spectrum of an element

The next model of the atom was developed by ...

Niels Bohr

(Bohr Model) Electrons move in ______ around nucleus.

Orbits

(Bohr Model) The energies of electrons in atoms are ...

Quantized

(Bohr Model) The energy of the photons corresponds to the ________ in energy between the orbits.

Difference

(Bohr Model) An _______ moves to higher energy orbit when a ______ is ...

Electron, photon, absorbed

A ______ is _______ when an _______ moves to lower energy orbit.

Photon, emitted, electron

Bohr’s model (electrons moving in defined orbits around nucleus at known energy levels) only works for ...

Hydrogen

A better way to represent the transitions of electrons upon absorbing or emitting photons is with ...

Energy Diagrams

Each energy level has a ________, the higher the number the higher the _______.

Quantum number, energy

Energy levels are NOT ______ (they represent ______ only)

Orbits, energy

Electrons transition between energy levels by _________ or _______ photons with energies equal to the exact difference in energy between the two levels.

Absorbing, emitting

Which color photon is emitted when an electron moves from level 2🡪1? A. Green B. Orange

Which photon is absorbed when an electron moves from level 1🡪3? A. Green B. Orange

Is the same amount of energy required to move an electron from n=2 to n=3? A. Yes B. No

Which of the following transitions for an electron in a hydrogen atom would release the largest amount of energy? A. n = 3 → n = 2 B. n = 4 → n = 2 C.n = 1 → n = 4 D. n = 2 → n = 1

Can a hydrogen atom absorb or emit every wavelength of light in the visible spectrum? A. Yes B. No

________, all matter has wave properties and, therefore, a wavelength λ.

de Broglie

________ – λ is much smaller than the object - no effect on properties

Macroscopic objects

____________ – λ similar in size to the object - affects properties

Atomic-scale objects (such as electrons)

What is the wavelength of an electron moving at 2.65 × 10^6 m s–1? Useful Information: λ = h/(mv) h = 6.626 × 10^–34 J s 1 J = 1 kg m2 s–2 Mass of an electron is 9.1 × 10^−31 kg

2.75 x 10^-10 m

Is the wavelength of a human (10–37 m) comparable to the size of a human (1-2 m)? A. Yes B. No

What is the evidence that electrons are waves? Diffraction and interference pattern of waves of ______ and ______.

Light, electrons

When electrons are used in the double slit experiment, they show an _______.

Interference pattern

Are electrons circling around the nucleus in orbits? A. Yes B. No C. Sometimes D. In the H atom, but no other atoms

________: regions of space where electrons with a certain quantized energy have a high probability of being found.

Atomic orbitals

Each orbital can be described by a set of ________ (n, l, ml) that are derived from quantum mechanical calculations.

Quantum numbers

A fourth quantum number, ______ , describes the electron spin.

m(sub)s

There ______ s orbital in a “set” or subshell.

Is only one

The ______ the principal quantum number, the ______ the orbital and the ______ the energy.

Larger, larger, higher

In a set of p orbitals, there ______ orbitals.

Are three

In a set of d orbitals, there ______ orbitals.

Are five

How many orbitals are in the electron cloud of one atom? A. Only the s orbital B. Only one p orbital C. Only the d orbitals D. All of the orbitals (all s, p, d, etc.) overlap within the electron cloud.

We often refer to elements by the location of their electrons in the ________ (_______)

Outermost orbitals, valence electrons

________ are ... - A closed shell of electrons is very stable – they don’t participate in reactions. - To identify: use the last noble gas (group 18, eg Ne or Xe) and any full d shell (transition metals).

Core electrons

________, these are the electrons that determine reactivity!

Valence electrons

Write the electron configuration for carbon and label the core and valence electrons ...

1s^2 2s^2 2p^2 -core--valence--

Write the electron configuration for chlorine and label the core and valence electrons...

1s^2 2s^2 2p^6 3s^2 3p^5 --------core----------valence---

What is the core/valence electron configuration of O? A. [He] 2s^2 2p^4 B. [Ne] 2s^2 2p^4 C. [Ne] 2s^2 2p^1 D. [He] 2s^2

How many core and valence electrons does N have? A. 2 core, 5 valence B. 5 core, 2 valence C. 4 core, 3 valence

How many valence electrons does P have? How about As? And Sb?

5, 5, 5

How many core and valence electrons does Si have? A. 10 core, 4 valence B. 4 core, 10 valence C. 12 core, 2 valence

How many valence electrons does C have? How about Ge? And Sn?

4, 4, 4

(___________) Originally developed by Mendeleev On basis of experimental behavior and repeating (periodic) patterns He left spaces for undiscovered elements Originally on basis of increasing atomic mass - then on atomic number Really electron organization explains repeating patterns

Periodic Table

What is the electron configuration for Br? A. [Ar] 4s2 4p5 B. [Ar] 4s2 3d10 4p5 C. [Kr] 4p5

How many core and valence electrons does Br have? A. 18 core and 17 valence B. 28 core and 7 valence C. 35 core and 0 valence

We are making the claim that electrons are in orbitals with quantized energies. What is the evidence for this?

Periodic trends

The atomic radius of Na is ________ than that of Li. A. larger B. smaller C. no different

The atomic radius of Ne is ________ than that of Li. A. larger B. smaller no different

What happens to the force (F) if q1 or q2 increases? A. increase B. decrease C. stays same

What happens to the force as r increases? A. increase B. decrease C. stays same

The atomic radius represents the state where the _______________ between the electrons and protons are _____ to the _________________ between the electrons.

Forces of attraction, equal to, forces of repulsion

Effective nuclear charge _________ across a row.

Increases

What happens to the attractive force across a row? A. increases B. decreases C. stays same

Which of the following has the smallest atomic radius? A. Ar B. Al C. Ga D. Kr

If an electron is removed from an atom, what is the charge of the ion? A. Neutral B. Positive C. Negative D. It depends on the element

The outermost electron is removed resulting in a cation. Cations are ___________ charged.

Positively

Which has a larger radius? A. Li B. Li+ C. Same

If an electron is added to an atom, what is the charge of the ion? A. Neutral B. Positive C. Negative D. It depends on the element

An electron is added to the next available (lowest energy) orbital. Anions are ________ charged.

Negatively

Which has the largest radius? A. F B. F– C. Same

Which is larger? Na+ or F– A. Na+ B. F– C. Same

_________: energy required to remove an electron from an atom in the gas phase.

Ionization Energy

Compare Li and Na. Which is easier to remove an electron from? A. Li B. Na C. Same

The ionization energy of Na is __________ than that of Li. A. larger B. smaller

Compare Li and Ne. Which is it easier to remove an electron from? A. Li B. Ne C. Same

The ionization energy of Ne is _________ than that of Li. A. larger B. smaller

(Trends Down a Group) Atomic radius ________, ionization energy ________.

Increases, decreases

(Trends Across a Row) Atomic radius ________, ionization energy ________.

Decreases, increases

The trends in radius and IE are _________ but caused by the same phenomenon – the _________.

Inversely related, effective nuclear charge

Which ionization energy is largest? A. First IE: Mg (g) 🡪 Mg^+ (g) + e^- B. Second IE: Mg^+ (g) 🡪 Mg^2+ (g) + e^- C. Third IE: Mg^2+ (g) 🡪 Mg^3+ (g) + e^-

IE1 1,012 kJ/mol IE2 1,900 kJ/mol IE3 2,910 kJ/mol IE4 4,960 kJ/mol IE5 6,270 kJ/mol IE6 22,200 kJ/mol IE7 26,345 kJ/mol Which element in period three would most likely show this trend in ionization energies? A. Mg B. Al C. Si D. P E. S