Sig Figs and Conversion
The average width of a human hair is 89 μm.
Express this width in kilometers.
8.9 x 10^-8 km
What is Ca?
Alkaline earth metal, main metal, cation (+2 charge)
What is the photoelectric effect?
When light shines on a metal, electrons can be ejected from the surface of the metal when the energy of light overcomes the threshold frequency of the metal.
What is the relationship between wavelength, frequency, and energy?
Wavelength and frequency have an inverse relationship
Wavelength and energy have an inverse relationship.
Frequency and energy are directly proportional.
What are the quantum numbers?
n- principal quantum number, l-angular momentum quantum number, ml- magnetic quantum number, ms- spin quantum number
(26.14/3.38) +4.2
correct number of sig figs
11.9
Label where the cation and anions would be on the periodic table and their charges?
Group 1: +1, cation
Group 2: +2, cation
Group 17: -1, anion
Group 16: -2, anion
Group 15: -3, anion
How many photons are contained in a flash of green light (wavelength = 525 nm) that contains 189 kJ of energy?
4.99 × 10^23 photons
What is the order of the electromagnetic spectrum from low energy to high energy?
radio, microwave, infrared, red, orange, yellow, green, blue, purple, UV, x-ray, gamma ray
What does the orbital look like that has the Angular Momentum quantum number l = 1?
Vertical figure eight
12. If 9.03 × 10^20 molecules of a xenon fluoride
compound weighs 0.311 g, what is the formula?
XeF4 207.3 g/mol
Look at the slide to see Na.
How many protons, neutrons, electrons?
protons- 11
electrons- 10
neutrons- 12
What is the energy of a mole of photons that have a frequency of 2.75 x 10^14 s? Give your answer in units of kJ/mol.
110 kj/mol
A microwave oven emits microwave radiation through food with a wavelength of 12 cm. What is the frequency of this radiation?
2.5 x 10^9s^−1
What are the two quantum numbers (n and l) that correspond to an orbital holding an outermost electron of arsenic, As?
n= 4
l= 1
Knowing that element Sb has two isotopes and
average atomic mass of 121.76 amu use the
following information to calculate the missing %
abundance “x” for Sb-121.
Sb-121 = 120.904 amu
Sb-123 = 122.904
57.2
In which group would you expect to find an element with the generic valence electron configuration of ns^2 np^4?
Group 16
A metal's Φ is 7.90×10-19 J. What is the longest wavelength of electromagnetic radiation that can eject an electron from the surface of a piece of the metal? (answer in nm)
252 nm
What is the difference between an emission spectrum and an absorption spectrum, in terms of both appearance and what occurs to produce the spectra?
An emission spectrum has a black background with colored lines and an absorption spectrum has rainbow background with black lines.
The electron configuration [Kr] 4d^10 could correspond to which ion(s)?
Sn^4+
Cd^2+
What volume in L of hexane has the same mass as 70.6
mL of chloroform?
Hexane density is 0.661 g/mL
Chloroform density is 1.479 g/mL
0.158 L
A main group element that has four electrons in its
outermost p-orbitals is most likely to ________.
(think about if it gains or lose electron and its charge)
gain two electrons and form an anion with a –2 charge.
Blue photons (475 nm) are incident on two metals, Mg and K. Which metal(s) will experience the
photoelectric effect?
Mg work function is 5.90 × 10^−19 J
K work function is 3.69 × 10^−19 J
K only
(see slides)
Which photonic emission has shortest wavelength?
A
Which species have the same number of unpaired
electrons? Select all answer choices that apply.
A. Se and Te
B. Rb and Si
C. As and P^3-
D. Na^+ and Mg^2+
A. Se and Te
D. Na^+ and Mg^2+