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100
How many significant figures is in the number: 0.006070
4 sig figs
100
Based on this diagram, which isotope of copper is least abundant?
Copper-65
100
How many valence electrons does chlorine have?
7 VE's
200
Write in scientific notation with 4 significant figures:
12,785,000
1.279 x 107
200
How many neutrons is in: 13C
7 neutrons
200
What is the electron configuration of argon.
1s22s22p63s23p6
300
Convert 12.60 mL --> L
0.0126 L
300
Calculate the average atomic mass of Boron. (4 sig figs)
10.83 amu
300
What is the noble gas configuration of arsenic?
[Ar]4s23d104p3
400
What is the mass of an atom with 8 electrons, 8 protons, and 10 neutrons.
18 amu
400
(4 sig figs)
28.08 amu
400
Draw the electron orbital diagram for magnesium.
500
Calculate the mass percent of hydrogen in hydroxide (OH) if hydrogen has a mass of 2.0 g and the total mass of OH is 17.0 g. (3 sig figs)
11.8% of H in OH
500
Nitrogen has two isotopes, N-14 and N-15. If the average atomic mass is 14.007 amu, what is the abundance of isotope N-15? (Write answer with 2 sig figs)
0.70%
500
Atoms are more stable when their outer energy level is full. For most elements, this means having how many electrons in their outer energy level?
8 electrons (octet)
Stability here just means the electrons are in a lower-energy, more comfortable arrangement.