Chempardy Exam 1

Name that Chemical Substance

100

Which element has 0 neutrons?

Hydrogen

200

[Xe] 4f¹⁴5d¹⁰6s¹

Gold (Au)

300

33 protons, 36 electrons, 42 neutrons

⁷⁵₃₃As^3-

400

Name the following polyatomic ions: ClO₄⁻, SO₄²⁻, MnO₄⁻

Perchlorate, Sulfate, Permanganate

500

Name the following compounds: ZnCl₂, HNO₂, CTe₂

Zinc Chloride, Nitrous Acid, Carbon Ditelluride

Periodic Trends

100

Which element has a greater difference in energy between first and second ionization energy: K or Mg?

Potassium (K)

200

Which of the following atoms has the most exothermic electron affinity: S, Cl, Br, O?

Chloride (Cl)

300

Which of the following isoelectronic ions is the smallest: Sr⁺², Kr, Ge⁴⁻, In³⁺?

In³⁺

400

Rank the following ions in order of increasing size: N³⁻, Ca²⁺, Cs⁺¹, O²⁻

O²⁻ < N³⁻ < Ca²⁺ < Cs⁺¹

500

Rank the following elements in order of increasing third ionization energy: Sr, In, Na, Br.

In < Br < Na < Sr

Energy Levels

100

Which color of visible light has the lowest frequency?

Red

200

Calcium-40 emits a gamma ray that has an energy of 4.3 µeV. What is the wavelength of this gamma ray? (1 eV=1.602E-19 J)

0.29m

300

Write both forms of the Ryberg equation. Include units.

1. E = -2.178x10^-18J (1/n_f2-1/n_i2) 

2. 1/lambda=1.0968x10⁷1/m(1/n_f2-1/n_i2)

400

The energy emitted from an electron initially in the fifth energy level is 1.55E-19 J. Which energy level does the electron end up in?

n=3

500

An electromagnetic wave has a wavelength of 7276 nm. Calculate the frequency of one photon of this radiation.  

4.12 E13 Hz

Quantum Mechanical Model

100

Which angular momentum integer represents a 4f subshell?

3

200

Write an allowed set of quantum numbers for an n=3 electron

n=3  L= 0, 1, 2 mL=-2, -1, 0, 1, 2 mS: 1/2 , -½

300

What does the principal quantum number describe?

Size & energy of an orbital

400

What is the Aufbau principle, what are its exceptions?

Electrons fill lower energy orbitals before higher energy orbitals, when Z>30 (half filled/fully filled orbitals are more stable)

500

Write the noble gas electron configuration and arrow diagram of Sr²⁺

[Kr]

Bonding

100

Which of the following compounds will have the most ionic bond: NO, SrF₂, CF₄

SrF₂

200

What compounds are diatomics?

Br, I, N, Cl, H, O, F

300

Describe 2 differences between ionic and covalent bonds, and provide an example of each type of bond.

1. Covalent: Sharing electrons, small/no difference in electronegativity, can be polar or nonpolar

2. Ionic: Transfer of electrons, conducts electricity when melted, forms ions, large difference in electronegativity

400

Draw the Lewis structure of C₂H₃N

500

Calculate the change in enthalpy using the bond energies provided for the following reaction.  

-160