Download Unit 1 Answer Key

Unit 1 Answer Key
PS 1A - #5,7,9,30,32,36,40,44 (8)
(5) Mass before reaction = mass after reaction. Give an example to demonstrate (digestion, burning log …)
(7) Gas is compressible fluids. Liquid is non-compressible fluids. Solid is non-compressible non-fluids.
(9) <example of element, compound, heterogeneous mixture, homogeneous mixture (aka, solution)>
(30) 0.2 g hydrogen
(32) 133 g bromine
(36) Physical change, chemical change, chemical change, physical change
(40) Physical property, chemical property, physical property, chemical property, physical property
(44) Chemical reaction, physical process, physical process, physical process, chemical change
PS 1B - #12,13,14,16,17,18,50-60 even, 64-72 even (17)
(12) Precision is getting the same answer (hopefully the accurate one) repeatedly. Indicated with sig figs.
(13) In mult/div, keep lowest number of sig figs. In add/subtr, keep lowest number of decimal places. <Ex>
(14) Measured number is measured by comparison to a standard (height, weight, etc…) Exact number is
established by definition (1 foot = 12 inches, the 1 and 12 are exact numbers with a bazillion sig figs)
(16) Length = meter (3.37 inches longer than a yard) Mass = kilogram (2.20 lbs, though pounds is force)
(17) Absolute temp is a scale with lowest possible temp = 0°. K = C + 273
(18) Density = mass/volume. It is a physical property that can be used to identify materials (eg., jade).
(50) 4, 3, 6, 4, 4, 4
(52) 150,000,000 km = 1.50 x 108 km (notice how sig figs are more obvious in scientific notation)
(54) 0.34, 0.007, 17.867, 1.010
(56) 2.8 cm3 of iron
(58) 4.851 g, 3.16 cm, 2.591 ns, 8.93 pg
(60) 8.55x103 m, 1.98x10-9 s, 2.54x10-2 m, 6.923x10-6 g
(64) -321°F
(66) 0.714 g/cm3
(68) 7.1 g/cm3 cassiterite
(70) 16 g
(72) 28.5 mL
PS 1C - #74-82 even,118,122,128,134,(140 EC) (10)
(74) 4.83x105 g
(76) 9.6x10-8 mm
(78) 1.4x10-15 L
(80) 2.58x103 J
(82) 1.5x109 m3
(118) 2.76 g/cm3
(122) 0.050 L
(128) 4.77x1011 L
(134) 2.4 L
(140) 14 karats