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Test 2

• The periodic table is organized bya. Increasing proton number

b. Increasing atomic mass

c. Increasing neutron number

d. alphabetically

• Which compounds are identical?– Compound A 10 g 2 mL– Compound B 40 g 8 mL– Compound C 5 g 2 mL– Compound D 40 g 5 mL

a. compounds A & B

b. compounds A & C

c. compounds B & C

d. compounds B & 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 = fertilizer dependent = plant

growth

– Time in evaporation experiment• Independent = time dependent = evaporation

– Temperature in experiment to determine the heat produced by candle waxes

• Independent = candle wax dependent = 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, 0.90

1 2 3 4

Accurate? Yes Yes No No

Precise? No Yes No Yes

Midterm Review Answers• Dimensional Analysis

– 14.8 hours– 2300 grams– 34 meters– 5.8 meters

• Scientific Notation– 3.2 x 10-5

– 2.7 x 1012

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 produced2. Color Change3. Change in smell4. Formation of solid—precipitate5. Light is produced6. 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– 1s2, 2s2, 2p6

– 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

He42 01 00

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 produced2. Color Change3. Change in smell4. Formation of solid—precipitate5. Light is produced6. 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

Isotope Gamma Alpha Chemical Physical

Half life Proton Gas Float Density

Homogeneous

Fusion Fission Endothermic Liquid

8 14 6 Precision Solid

Neutron Electron Increase Decrease Free 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 ______ protonsa. 14

b. 8

c. 6

• Phase of matter with the most kinetic energy

a. solid

b. liquid

c. gas

• Ice meltinga. 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 calleda. 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