Yes, I graded your tests… I’m passing them back now Have your midterm review guide answers out. Remember, this was for homework! MIDTERM IS TOMORROW!!!!!! This counts 5% of your final grade!

Test 2 The periodic table is organized by a.Increasing proton number b.Increasing atomic mass c.Increasing neutron number d.alphabetically

Which compounds are identical? –Compound A10 g2 mL –Compound B40 g8 mL –Compound C 5 g2 mL –Compound D40 g5 mL a. compounds A & B b. compounds A & C c. compounds B & C d. compoundsB & D e. none are the same

There is an unknown metal. What data could you collect to identify it? a.Color b.Mass c.Density d.temperature

Midterm Review Guide Answers Dependent vs Independent Variable –Independent- what we change the cause –Dependent- what changes & we observe, the effect –Fertilizer in plant growth experiment Independent = fertilizerdependent = plant growth –Time in evaporation experiment Independent = timedependent = evaporation –Temperature in experiment to determine the heat produced by candle waxes Independent = candle waxdependent = temperature

Midterm Review Guide Answers Lab equipment –Volume Graduated cylinder –Mass Triple beam balance –Meniscus Read volume

Midterm Review Answers Significant Figures –Groups of data go up and down –0.89, 0.91, Accurate? Yes No Precise? NoYesNoYes

Midterm Review Answers Dimensional Analysis –14.8 hours –2300 grams –34 meters –5.8 meters Scientific Notation –3.2 x –2.7 x 10 12

Midterm Review Answers Physical/Chemical Change –Chemical change = iron rusting –Water displacement = volume = extensive –Color = intensive

Changes in Matter Evidence of chemical reaction: 1.Gas is produced 2.Color Change 3.Change in smell 4.Formation of solid—precipitate 5.Light is produced 6.Temperature change -exothermic -endothermic

Midterm Review Answers Solids, liquids, gases –Liquid = Fixed volume, variable shape –Gas = Highest kinetic energy –Gas = Variable shape, variable volume –Solid = Particles vibrate around a central point –Gas = Compressible –Gas = Most kinetic energy

Midterm Review Answers Heterogeneous / Homogeneous –Heterogeneous = looks different, not uniform –Homogeneous = looks same, uniform –Homogeneous = Kool Aid

Midterm Review Guide Density –2 g/mL –Sink b/c density is greater than 1 –Aluminum has a density of 2.63 g/mL. Which one is aluminum? Choice 1: Mass = 427 g Volume = 175 mL Choice 2: Mass = 526g Volume= 200 mL

Midterm Review Answers Atomic Structure –Ba: 81 neutrons (81.3), 56 protons, 56 electrons –20 amu (10 protons + 10 neutrons) –14 neutrons (26-12) –Neutron –Rutherford found the nucleus of an atom –1s 2, 2s 2, 2p 6 –Electrons releasing light as they fall back to their ground state orbital

Midterm Review Answers Isotopes –6 P+, 8 No, 6 e- –Neutrons Atomic Mass –Atomic Mass = protons + neutrons –Which would have the greatest effect on the atomic mass? –30 %Iron-56 –60%Iron-57 –10%Iron-59

Midterm Review Answers Conservation of Mass –Each side must have the same number of atoms of each element Electron Configuration –Sulfur –Down (up, up, up, down) –S orbital =2, p orbital = 6, d orbital = 10, f orbital = 14 –6 valence electrons

Midterm Review Answers Alpha, beta, gamma –Gamma- most penetrating –Alpha- positive –Gamma – no mass, no charge –Beta - electron

Midterm Review Answers Fission/Fusion –Nucleus split in two Fission –Occurs on the sun –Combining of 2 nuclei into one Fusion

Midterm Review Answers Half Life –12.5 grams –6 half lives Radioactive Waste –Nuclear waste is radioactive; the problem is storage –No

Midterm Review Answers Indicators of a chemical change –Change in color –Change in temperature Evidence of chemical reaction: 1.Gas is produced 2.Color Change 3.Change in smell 4.Formation of solid—precipitate 5.Light is produced 6.Temperature change -exothermic -endothermic

Midterm Review Answers Neutral Atom –10 P+, 10 e-, 10 N0 Kinetic/Potential Energy –Kinetic = energy of motion –Potential = stored energy –A skydiver in freefall –Gas

Midterm Review Answers Exothermic / Endothermic Reactions –Exothermic = energy is released –Endothermic = energy is absorbed Endothermic = Temperature decreases Exothermic = Fire Endothermic = Cold compression pack Endothermic = Ice melting

Midterm Review Answers Dependent / Independent Variables –Fertilizer or growth rate of plants Independent = fertilizer Dependent = growth rate –Increase in heat or speed of molecules Independent = increase in heat Dependent = speed of molecules

Midterm Review Answers Periodic Table –Solid –Families are vertical –4 energy levels –6 valence electrons

Bingo! Put the following words on your Bingo card IsotopeGammaAlphaChemicalPhysical Half lifeProtonGasFloatDensity Homogene ous FusionFissionEndothermicLiquid 8146PrecisionSolid NeutronElectronIncreaseDecreaseFree space

State of matter with variable shape and variable volume a. solid b. liquid c. gas

Number of valence electrons in carbon a. 14 b. 12 c. 8 d. 6

Time needed for ½ of radioactive nuclei to decay a. isotope b. homogeneous c. half life

Type of radiation that is made of a helium particle and can be stopped with paper a. alpha b. beta c. gamma

Si (Silicon) has ______ protons a. 14 b. 8 c. 6

Phase of matter with the most kinetic energy a. solid b. liquid c. gas

Ice melting a. endothermic b. exothermic

Density of water is 1.0 g/mL Which set of data would be precise but not accurate? a. 1.22, 1.70, 0.82 b. 0.85, 0.87, 0.86 c. 1.01, 1.00, 1.03

Milk souring is an example of a a.Physical change b.Chemical change

How many neutrons in Carbon-14? a. 14 b. 8 c. 6

State of matter that has particles that vibrate and are close together a. solid b. liquid c. gas

Combining nuclei is called a. fission b. fusion

When an object has a density of less than 1 g/mL, we know the object will ________ in water a. sink b. float

Nuclei are radioactive when they become unstable due to the ratio of neutrons to a. protons b. electrons

Protons are the same mass and _______ a. neutrons b. electrons

Salt water and kool-aid are examples of a. heterogeneous mixture b. homogeneous mixture

Ice melting is an example of a.Physical change b.Chemical change

Subatomic particle that is outside the nucleus and carries a negative charge a. proton b. neutron c. electron

Type of radiation that goes through paper and foil but not concrete a.Alpha b.Beta c.Gamma

Splitting a nucleus into many nuclei is called a. fission b. fusion

The particles’ speed ________ when we change from a solid to liquid a. increase b. decrease

Atoms with the same number of protons but a different number of neutrons a. half life b. isotope c. element

Is equal to mass ÷ volume a. half life b. density c. mass d. volume

The particles’ speed _______ as we change from a gas to a liquid a. increase b. decrease