Atomic Theory & more
Wavelength, Energy, Frequency
Electron Configuration + quantum numbers
Conversion
Random
100
What does this describe:
In 12g of NO2, and in 34 g of NO2, the mass percent of N and the mass percent of O stay the same.
The law of definite (constant) composition
100
What has a greater wavelength? Red or blue light? 
Red: has longer wavelengths (around 600-700)
blue is on the shorter end (so violet has the shortest wavelength)
100
Using shorthand notation, what is the electron configuration for Ga?
[Ar]4s2 3d10 4p1
100
How many moles are in 3.4 x 10^23 molecules of O2?
3.4 x 10^23 x (1 mol / 6.022 x 10^23) = 0.56 moles
100
How many core & valence electrons does Si have?
4 valence electrons, 10 core electrons
200
Chlorine has an atomic mass of 35.45, and has two isotopes. One isotope has a mass of 34.968 g and accounts for 75.76%, the other isotope accounts for the other 24.24%. What is the mass of the second isotope?
35.45 = (34.986 x 0.7576) + (0.2424)x
35.45 = 26.5 + 0.2424x
35.45 - 26.5 = 8.95
8.95 = 0.2424x
8.95/0.2424 = x
x = 36.9 g
200
What is the frequency in Hz associated with a wavelength of 888 nm?
c = w f
(3 x 10^8) / (888 x 10^-9) = f
f = 3.38 x 10^14 Hz
200
What is incorrect about this electron configuration for Pb:
[Xe]6s2 5d10 6s2
forgetting 4f 14
200
If you have 25 g of CH4, how many molecules do you have?
25 g CH4 x (1 mol / 16.042 g) x (6.022 x 10^23 / 1 mol) = 9.4 x 10^23 molecules
200
Which of the following statements is correct:
a) CO2 is a molecular formula and empirical formula.
b) CH3 and C3H6 have the sample empirical formula
c) The empirical formula of S4O8 would be S2O4
A is correct
300
What is the likely charge on Oxygen?
2-
300
What is the energy in J associated with a wavelength of 2.3 m?
c = wf
(3 x 10^8 m/s) / 2.3 m = f = 1.3 x 10^8 Hz
E = (6.626 x 10^-34) (1.3 x 10^8)
E = 8.6 x 10^-26
300
Which one of these IS isoelectronic with a rubidium ion?
a)K+
b) Ca2+
c) Br-
d) S2-
c) Br-
300
In a sample of gaseous hydrogen, there is 7.2 x 10^24 molecules. How many grams is this?
7.2 x 10^24 x (1 mol / 6.022 x 10^23) x (2.016 g / 1 mol) = 24.1 grams
300
Draw the orbital diagram for chlorine.
400
Which isotope has the greatest number of neutrons?
a) chlorine-36
b) carbon-14
c) silicon-29
A
400
What is the frequency associated with a wavelength of 345 nm?
(3 x 10^8 m/s) / (345 x 10^-9 m) = f
f = 8.70 x 10^14 Hz
400
In what subshells do valence electrons exist?
s and p (of the highest principle quantum number)
400
Which of these is a greater number of moles:
4.22 g of CH2F2
4.22 g of HCl
4.22 g CH2F2 x (1 mol / 52.02g) = 0.0811
4.22 g HCl x (1 mol / 36.46g) = 0.116 mol
= HCL
400
Categorize these 4 compounds into covalent and ionic compounds.
a) NaCl
b) CH4
c) H2O
d) KOH
Ionic: A + D
Covalent: B + C
500
Which represents the largest number of atoms:
a) 1 mol of CO2
b) 2 mol of SF4
c) 3 mol LiCl
2 mol SF4
500
What is the wavelength, in m, associated with an energy of 8.7 J?
E = hf
8.7 J / (6.626 x 10^-34) = f
f = 1.3 x 10^34 Hz
c = wf
(3 x 10^8) / (1.3 x 10^34) = w
w = 2.3 x 10^-26
500
Which of these is the correct electron configuration for Sb?
a) [Kr]5s2 4d10 5p5
b)[Kr]4d10 5s2 5p3
c) [Kr] 5s2 4d10 5p3
C
500
How many grams are in 7.84 x 10^25 molecules of SO4?
7.84 x 10^25 molecules x (1 mol/6.022 x10^23) x (96.06 g / 1 mol) = 1.25 x 10^4 grams
500
Without looking at a periodic table, give an example of a halogen.
F, Cl, Br, I (group 7)