Significant Figures
5 sf
Convert 150cm to m
1.5m
Identify the group name for Br and I.
Halogens
How many protons, neutrons, and electrons are in 35Cl-?
17 protons, 18 neutrons, 18 electrons.
What isotope of Sulfur (32S or 34S) is most abundant if its atomic weight is 32.06amu?
32S
Solve: 131.30+0.039 to correct sf
131.34
Convert 2.5kg to g
2.5 x 10^3 g
Which element is a metalloid: B, C, S, In, or Pb?
Boron
How does a neutral atom become a -2 ion?
By acquiring two additional electrons.
Explain why average atomic mass on the periodic table is rarely a whole number.
Because it is a weighted average of all naturally occurring isotopes based on their percent abundance, rather than a single isotope's mass.
Solve: 150.56/0.0035 to correct sf
4.3 x 10^4
Convert 45.2 miles/hour to m/s (1mi=1.609km)
20.2 m/s
Identify the alkali earth metal with the highest atomic number.
Radium
Compare Atom A (23p, 31n, 18e) and Atom B (23p, 31n, 16e). How are they related?
They are ions of the same element (Vanadium)
Calculate the average atomic mass of X if 75.0% is 35.0 amu and 25.0% is 37.0 amu.
35.5 amu
State the sig fig rule for addition/subtraction vs. multiplication/division.
Addition/Subtraction rounds to the least number of decimal places; Multiplication/Division rounds to the least number of total significant figures.
Calculate the density of a 1.25cm cube weighing 13.435 g.
6.89 x 10^3 kg/m^3
Classify NH3, pure gold, and a chocolate almond.
NH3 = Compound; Pure Gold = Element; Chocolate Almond = Heterogeneous Mixture.
Which of Ca, K, Al, Br, or Si is most likely to form a +1 ion?
Potassium (Alkali Metal)
Element Y has two isotopes 10Y at 10.0 amu and 11Y at 11.0 amu. If average mass is 10.81 amu, which is more abundant?
11Y
Express 0.00004050m in correct scientific notation with proper sig figs.
4.050 x 10^-5 m
Convert 13.6 g/cm^3 to kg/m^3
1.36 x 10^4 kg/m^3
Identify the least metallic element: C, Si, Ge, Sn.
C (Carbon) (Metallic character increases going down a group).
Differentiate mass number vs. atomic mass vs. atomic number.
Atomic Number: Number of protons.
Mass Number: Protons + Neutrons (integer for a specific isotope).
Atomic Mass: Weighted average mass of all naturally occurring isotopes.
35Cl (34.969 amu) and 37Cl (36.966 amu) have an average mass of 35.453 amu. Calculate % abundance.
35Cl: 75.76%, 37Cl: 24.24%