Warm Up 9-1-151. Classify the following as pure substance or

mixture: kool aid, tap water, air, sugar packet2. What kind of pure substance is NaCl? 3. Name the two types of mixtures.4. An object has a density of 4 g/cm3 and a volume of 8 cm3, find its mass.

HomeworkTest Unit 1 + Notebook Check

AgendaTurn in Test Review worksheetGo over quizNotes Unit 2-1Lab Density Engineering

Quiz Unit 1• Version 11. 0.03652 kg2. 2396 cm3. 0.33 cm3 or 0.25 cm3

4. 180 g5. When mixing different

substances but they do not mix and result in layers. Ex. Cereal and milk

6. Bubbles, color change, temperature change, precipitate (forming solids particles

• Version 21. 6.53 kg2. 6.39 cm3. 0.5 cm3

4. 80 g5. When mixing different

substances and they mix thoroughly resulting in only 1 layer. Ex. Sugar in water

6. Bubbles, color change, temperature change, precipitate (forming solids particles

Unit 2-1Substances Are Made of Atoms

Atomic Theory

• States that atoms are building blocks of all matter.

• Three laws that support the current atomic theory

Atomic Theory

Current ModelElectron cloud instead of orbital

The atom model will change when new/better data come out

Atomic Theory

• Law of definite proportions - chemical compound always contain the same elements in the exact same proportions by mass.

C2H6O2

OxygenCarbonHydrogen

Atomic Theory• Law of conservation of mass – mass cannot be

created or destroyed. Mass in reactants equal the mass in products.

Sodium acetic carbon sodiumbicarbonate + acid --------> dioxide + acetate + H2O

2 grams 2 grams 4 grams total

baking soda

vinegar solution

Sodium acetate and water

CO2 gas

Atomic Theory• Law of multiple proportions - the masses of

one element which combine with a fixed mass of the second element, are in a ratio of whole numbers.

Chemical Name Formula RatioNitrogen monoxide NO 1:1Nitrogen dioxide NO2 1:2Nitrous oxide N2O 2:1Water H2O 2:1Hydrogen peroxide H2O2 1:1

Atomic Theory• Elements combine in whole numbers

Dalton’s Atomic Theory

• 1808 – John Dalton combined the three laws and revised the early Greek idea of atoms

• Part of his theory areincorrect by today’s standards because ofour technology

Dalton’s Atomic Theory1. Matter is made of atoms, which cannot be

subdivided into smaller components2. Atoms of a element are identical in their

physical and chemical properties3. Atoms of different elements differ in their

physical and chemical properties4. Atoms combine in simple, whole-number

ratios to form compounds5. Atoms are rearrange in a reaction but not

created, destroyed or changed (transformed)

Engineering Challenge• Density and Archimedes’ Principle

-Create a boat to hold as much pennies as possible without sinking

Assignments

Notebook checklist • 5 days of notes = 25 points– Warm ups - questions/answers/date– Notes - Cornell format– Summary with signature

Online homework• Extended till 9PM tonight