Express each answer in scientific notation with the correct number of sig figs.
2.35 + 4.57 + 5.1 + 8.697=
2.07e1
How many d orbitals are contained in a d subshell?
5
Give the name of the compound with the formula PCl5.
***spelling counts****
phosphorus pentachloride
How many total valence electrons are in a molecules of water? (H2O)
8
How many neutrons are there in the nucleus of 108^Ag?
61
What is the best answer to report for (629 x 0.0045) + 22.11?
24.9
How many electrons can be present in all orbitals with n = 4 and ℓ = 1?
6
What is the formula of dinitrogen tetroxide?
N2O4
In the best Lewis structure of SO3 (sulfur trioxide) that obeys the octet rule, what is the formal charge on sulfur?
+2
How many protons and electrons are present in a Ca2+ ion?
20 protons, 18 electrons
Use scientific (exponential) notation to express the following quantities in terms of the given SI base units.
(Enter your answer using one of the following formats: 1.2e-3 for 0.0012 and 1.20e+2 for 120.)
(a)
0.237 nm to meters
2.37e-10 m
Of the following, which element has the highest first ionization energy, IE1?
Al
Cl
Na
P
Cl
Write the systematic name of the compound, Ca(NO3)2. (Spelling counts.)
Calcium Nitrate
(caps does not matter)
Based on the best Lewis structure for the cyanide ion, CN-, what is the formal charge on nitrogen?
0
A sample of chemical X is found to contain 5.0 grams of oxygen, 10.0 grams of carbon, and 20.0 grams of nitrogen. The law of definite proportion would predict that a 61 gram sample of chemical X should contain how many grams of carbon?
17 grams
Use scientific (exponential) notation to express the following quantities in terms of the given SI base units.
(Enter your answer using one of the following formats: 1.2e-3 for 0.0012 and 1.20e+2 for 120.)
(a)
74.1 Mm to m
7.41e7
(a) What is the wavelength (in nm) of light with a photon energy of 2.11e-19 J?
nm
(b) What is the frequency of light with a photon energy of 2.11e-19 J?
s-1
a) 941 nm
b) 3.18e14 s-1
Give the name or chemical formula (as appropriate) for each of the following inorganic acids. (Omit states-of-matter from your answer.)
carbonic acid(aq)
H2CO3
How many lone pairs are present on the central atom in the best Lewis structure of ClF3?
2 lone pairs
A fluorocarbon is known to contain only carbon, fluorine, and hydrogen. The first sample is measured to contain 12.10 g of carbon, 5.22 g of fluorine, and 1.94 g of hydrogen. If a second sample of the same fluorocarbon is measured to contain 34.50 g of carbon, what is the mass of the fluorine in the second sample?
14.9 grams
Which of the following is an example of a pure compound?
Water
Bread
Oxygen
Air
Salt water
Water
According to the Bohr model, what is the energy change, in joules, that occurs when an electron moves from the n = 3 to the n = 5 energy level of a hydrogen atom?
Recall: En = −2.180 ✕ 10−18 J
1/n2
.
1.55 ✕ 10-19 J
Give the name or chemical formula (as appropriate) for each of the following inorganic acids. (Omit states-of-matter from your answer.)
sulfuric acid(aq)
H2SO4
Which of the following molecules violates the octet rule by having more than eight electrons on the central atom?
CO2
NH3
SF6
SO2
BF3
SF6
A fluorocarbon is known to contain only carbon, fluorine, and hydrogen. The first sample is measured to contain 11.80 g of carbon, 22.42 g of fluorine, and 1.19 g of hydrogen. If a second sample of the same fluorocarbon is measured to contain 22.10 g of carbon, what is the total mass in grams of fluorocarbon in the second sample?
66.32 g