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Flashcards in Chapter 2 And 1.3 Deck (28):

Pure substance vs. mixture

Pure substance: all particles are the same and no & defined an constant

Mixture: different particle types
A combination of pure substances


Element vs. compound

Element: substance made form ONLY one type of atom

Compounds: substances made form 2 or more types o atoms


Physical properties vs. chemical properties

Physical: can be observed without changing identity of substance

Chemical: can only be observed when substances react with something else


Physical change vs. chemical change

Physical: a change in appearance, but no change in composition

Chemical: a new substance is formed


Extensive vs. intensive properties

Extensive: depends on substance amount ( mass and volume)

Intensive: does not depend on amount of substance. (Color, smell)


Solids vs. liquids vs. gases

Solid: independent shape, tight particles, has shape and volume.
Liquid: close particles, not independent shape
Gas: fills volume (expands), far apart particles


Reactants vs. products

Reactant: chronicles present at start of reaction

Product: chronicles produced in reaction


Exothermic vs. endothermic reactions

Exothermic: give off heat

Endothermic: absorbed heat


Four indications of chemical reaction

1. Transfer in energy (heat/light)
2. Change in color
3. Production of gas
4. Formation of precipitate


Defiance precipitate

A solid that forms and settles on the bottom of an aqueous solution


What does the law of conservation of mass state

In a physical and chemical change always stays the SAME

Product weight= reactant weight


Reversible vs. irreversible change

Reversible: melting and freezing

Irreversible: tearing paper



Everything with mass and volumes


What is the difference between an Observation and an Inference

Observation- information gathered using the 5 senses and measurement

Inference- conclusion based on the observations and past knowledge


Define chemistry

The study of matter and it's changes


Lab safety

Freakin common sense


Measuring to the correct decimal

Measure to what you can and guess once


Define an atom

Atom is smallest particle of an element that retains its identity in a chemical reaction


View of an atom changes overtime

1. Democritus
Thought atoms were solid spheres (smallest they get)
2. Dalton
Tough matter consisted of small lumps (atoms)
3. Thomson
Plumb pudding model (discovered electron and thought it would also have something positively charged)

4. Goldstein
He discovers the nucleus

5. Ruthoford
Electron cloud through tin foil experiment.
6. Bohr
Electron orbitals
7. Chadwick
Discovered the neutron


Compare and contrast subatomic particles (electron, proton, neutrons)

Electron e- -1 charge 1/1849 mass 9.11x10 to the -28th mass

Proton p+ +1 charge 1 mass 1.67x10 to the -24th mass

Neutron n0 0 charge. 1 mass 1.67x10 to the -24th mass


Interpret a nuclear symbol

Mass # is the top left
Atomic # is the bottom left
Charge is the top right

Mass - atomic number = neutrons



Atoms with different number of neutrons


Define average atomic mass and how to calculate it

It's the weight average of all the naturally occurring isotopes in that element. Found on periodic table below element symbol.


Describe how the Bohr of an atom improved upon earlier models.

It specified that electrons ain't in electron clouds but in specific paths (orbits) around the nucleus. The highest energy
Level is furthest from the nucleus.


Difference between quantum mechanical model and previous atom models.

This gives you the likeliness of finding an electron in various locations around the nucleus. No longer orbits (circular paths) but now Orbitals (area of location probability)


Define orbitals

Areas of location probability.


How to write electron configuration (3 rules)

See orange tab thing

1. Aufbau Principle
Build from the bottom up.
2. Pauli Exclusion (kinda like a magnet)
Each orbital may have a max. Of 2 electrons (opposite spins)
3. Hunds Rule (monopoly rule)
An electron must be on each property before adding


Now how to write a noble gas configuration

Ex [Ne] 2S2