MIDTERM REVIEW

ISOTOPE CALCULATION (5 minutes) Use the following data to calculate the average atomic mass of “element X” then use the periodic table to identify the element (show all work). Isotope Mass (amu) % Abundance X-16 15.995 99.762 X-17 16.999 0.038 X-18 17.999 0.20

ISOTOPE CALCULATION (5 minutes) Use the following data to calculate the average atomic mass of “element X” then use the periodic table to identify the element (show all work). ANSWER: 15.999 amu Oxygen Isotope Mass (amu) % Abundance X-16 15.995 99.762 X-17 16.999 0.038 X-18 17.999 0.20

ISOTOPE CALCULATION (5 Minutes) What is the atomic mass of hafnium if, out of every 500 atoms, 25 have a mass of 176, 95 have a mass of 177, 135 have a mass of 178, 70 have a mass of 179, and 175 have a mass of 180.0?

ISOTOPE CALCULATION (5 Minutes) What is the atomic mass of hafnium if, out of every 500 atoms, 25 have a mass of 176, 95 have a mass of 177, 135 have a mass of 178, 70 have a mass of 179, and 175 have a mass of 180.0? ANSWER: 178.55 amu

Protons, neutrons, electrons (10 minutes) 1. Give the number of protons, electrons, and neutrons in each of the following atoms. a) 10847 Ag b) 4020 Ca c) 2311 Na 2. Name each isotope and write it in hyphen notation and nuclear symbol notation. a) atomic number 26; mass number 56 b) atomic number 29; mass number 64 c) atomic number 17; mass number 37 3. How many protons, electrons, and neutrons are in each of the following isotopes? a) uranium-235 b) hydrogen-3 c) silicon-29 d) thorium-230

Protons, neutrons, electrons (10 minutes) 1. Give the number of protons, electrons, and neutrons in each of the following atoms. a) 10847 Ag b) 4020 Ca c) 2311 Na 2. Name each isotope and write it in hyphen notation and nuclear symbol notation. a) atomic number 26; mass number 56 b) atomic number 29; mass number 64 c) atomic number 17; mass number 37 3. How many protons, electrons, and neutrons are in each of the following isotopes? a) uranium-235 b) hydrogen-3 c) silicon-29 d) thorium-230 p=47, e=47, n=61 p=20, e=20, n=20 p=11, e=11, n=12 5626Fe Iron-56 6429Cu Copper-64 3717Cl Chlorine-37 p=92, e=92, n=143 p=1, e=1, n=2 p=14, e=14, n=15 p=90, e=90, n=140

Density (10 minutes) 1. A rectangular solid of unknown density is 10 cm long, 2 cm high and 4 cm wide.  The mass of this solid is 2.15 × 102 g. Find the density of the solid. 2. A rock has a density of 4 g/mL and a mass of 1.6 × 103 mg.  What is the volume this rock occupies?

Density (10 minutes) 1. A rectangular solid of unknown density is 10 cm long, 2 cm high and 4 cm wide.  The mass of this solid is 2.15 × 102 g. Find the density of the solid. 2.69 g/cm3 2. A rock has a density of 4 g/mL and a mass of 1.6 × 103 mg.  What is the volume this rock occupies? 0.4 mL

Electron configuration (5 minutes) 1. Write the electron configuration for Silver 2. Write the electron configuration for Tungsten

Electron configuration (5 minutes) 1. Write the electron configuration for Silver 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d9 2. Write the electron configuration for Tungsten 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d4

Metric conversions (8 minutes) 1. Convert 5.342 x 1015 pm = __________ cm 2. Convert 856 cm = ___________ km 3. Convert 3.5x106 µm = ______________ hm

Metric conversions (8 minutes) 1. Convert 5.342 x 1015 pm = _5.342x105_________ cm 2. Convert 856 cm = ___8.56x10-3________ km 3. Convert 3.5x106 µm = __3.5x10-2____________ hm

1 hr = 60 min 1 min = 60 sec 1 ton = 2000 lbs 7 days = 1 week 24 hrs = 1 day 1 kg = 2.2 lbs 1 gal = 3.79 L 264.2 gal = 1 cubic meter 1 mi = 5,280 ft 1 kg = 1000 g 1 lb = 16 oz 20 drops = 1 mL 365 days = 1 yr 52 weeks = 1 yr 2.54 cm = 1 in 1 L = 1000 mL 0.621 mi = 1.00 km 1 yd = 36 inches 1 cc is 1 cm3 1 mL = 1 cm3 Dimensional Analysis 1. If a projectile travels 3.00 x 103 feet in one second, how far will it travel in 18 minutes? 2. If a swimmer swims 85.4 yards in five minutes, how many meters will s/he swim in 70.0 seconds? 3. The orbital speed of Mars is 24.2 km per second. What is its speed in miles/hour?

Dimensional Analysis 1. If a projectile travels 3.00 x 103 feet in one second, how far will it travel in 18 minutes? 3.24x106 feet 2. If a swimmer swims 85.4 yards in five minutes, how many meters will s/he swim in 70.0 seconds? 18.2 m 3. The orbital speed of Mars is 24.2 km per second. What is its speed in miles/hour? 5.41x104 miles/hour

Mass/moles/atoms (20 Minutes) 1. What is the mass of 2.53 moles of lead (II) nitrate 2. Calculate the number of moles in a 3.75g sample of calcium carbide CaC2. 3. Calculate the number of moles in 2.66 x 1022 atoms of potassium iodide. 4. How many molecules are in a 65.6g sample of magnesium chloride. 5. Calculate the mass contained in 15.62x1030 atoms of barium bromide.

Mass/moles/atoms (20 Minutes) 1. What is the mass of 2.53 moles of lead (II) nitrate Pb(NO3)2 8.38x102 g Pb(NO3)2 2. Calculate the number of moles in a 3.75g sample of calcium carbide CaC2. 5.85x10-2 mol CaC2 3. Calculate the number of moles in 2.66 x 1022 atoms of potassium iodide. 4.42x10-2 mol KI 4. How many molecules are in a 65.6g sample of magnesium chloride. 4.15x1023 molecules MgCl2 5. Calculate the mass contained in 15.62x1030 atoms of barium bromide. 7.71x109 g BaBr2

Percent error (3 minutes) A student calculated a mass to be 250 g, but upon measuring it, found the mass to be 240 g. What is the percent error?

Percent error (3 minutes) A student calculated a mass to be 250 g, but upon measuring it, found the mass to be 240 g. What is the percent error? 4%

Percent mass (8 minutes) 1. A 134.50 g sample of aspirin is made up of 6.03 g of hydrogen, 80.70 g of carbon, and 47.77 g of oxygen. What is the percent by mass of each element in aspirin? 2. A 2.89 g sample of sulfur reacts with 5.72 g of copper to form a black compound. What is the percentage composition of the compound?

Percent mass (8 minutes) 1. A 134.50 g sample of aspirin is made up of 6.03 g of hydrogen, 80.70 g of carbon, and 47.77 g of oxygen. What is the percent by mass of each element in aspirin? 4.48% H, 60% C, 35.52% O 2. A 2.89 g sample of sulfur reacts with 5.72 g of copper to form a black compound. What is the percentage composition of the compound? 33.6% S, 66.4% Cu