Physical Science Review Sheet for Mid-Term EXAM o___O from VIVIAN

Physical Science Review Sheet for Mid-Term EXAM o___O From Vivian Krub

Introduction of Matter
Chapter 1

1) What is matter?
 Matter is anything that has mass and take up space. (3 different types of matter)
a) Solid
b) Liquid
c) Gas
 Volume is how much space something takes up (liquid + solid).
a) Regular shape volume: L x W x H = cm3, m3, km3
b) Volume of Liquid: Cylinder
c) Irregular shaped solid: drop in water in cylinder, and see how much H2O is displaced. 1ml=1cm3
 Mass is what an object made out. (kg, g, mg)
 Weight: Mass x Gravity (Gravity on Earth: 9.8m/s)
 Density: Mass
Volume
 Inertia is the tendency of an object to resist being moved. The more massive an object is, the greater its inertia.
 Things will float in water if the object is less than 1 g/ml, if it’s over then it will sink. Things float better in salt water because salt water is denser, it has more density.
2) Physical Properties
 Physical properties can describe what an object is without changing the object’s identity.
 PHYSICAL CHANGES DO NOT CHANGE WHAT THE OBJECT IS, AND PHYSICAL CHANGES YOU COULD REVERSE IT!
 Examples of Physical Properties: Thermal Conductivity (conduct heat, transfer heat), Solubility (dissolve easily), Ductility (could be pulled into wire), Malleability (could be rolled into thin sheets), Color, Shape, Size, Texture, Weight, Volume, Density, Magnetic, State, Smell, Odor, Thermal Conductivity
 Some examples of Physical Changes: Melting metals, melting ice, cutting paper, crushed aluminum can…
3) Chemical Properties
 Chemical properties are a property of matter that describes a substance’s ability to participate in chemical reactions.
 Another word for chemical change is a “Reaction”.
 CHEMICAL CHANGES CHANGE WHAT IT IS, FORM SOMETHING NEW, AND IT COULDN’T BE CHANGE BACK!
 Examples of Chemical Properties: Bubbles formation, release of gas, change in temperature, fire, smoke, light, change in smells, interaction, rusted, flammability, reactivity.
 Some examples of Chemical Changes: soured milk, fireworks.
 Understand the lab we had done about Physical and Chemical Reaction. (White before your eyes)

Chapter 2

1) Types of Matter
 Solid: particle are closed together, they don’t move fast enough to break the bonds. Shape and Volume stays the same.
 Liquid: particle starts to move fast enough to get away from each other, but don’t fully break apart. Shape changes, but volume stays the same.
 Gas: particle moving so fast that it is fully broken apart. Volume and shape changes.
 Amorphous solids: solids that don’t have a specific arrangement. (Ex. Gel, Wax, Clay.)
 Crystalline solids: solids with a definable shape. (Ex. Crystal, diamond, Safire.)
 Two properties of Liquid:
a) Surface tension: when molecules of H2O at the surface come close together, and act like solid. (Small insects could walk on it)
b) Viscosity: how well liquid flow. (High viscosity: Honey, oil) (Low viscosity: Water, milk)
2) Behavior of gases
 Pressure
a) Forces that press together (compress, squeeze, crunch)
b) If pressure increased on gas, molecules hit each other often.
 Temperature increases, volume increases. (Gas)
 Boyle’s Law: States that at a constant Temperature, the volume and pressure of a gas are inversely (indirectly) proportional.
a) As pressure increases then volume decreases.
b) As Volume increases then pressure decreases.
c) P x V = K (Constant)  Temperature have to stays the same.
 Charles’s Law: States that temperature and volume are directly proportional with a constant pressure for a GAS.
a) As temperature increases then volume increases.
b) As temperature decreases then volume decreases.
c) Volume
Temperature
 It takes lesser time to boil water because at sea level the water boils when the temperature reach 100C, but up at mountain it only need to reach 90C.

3) Changes of state
 Names for each state change:
a) Sublimation- Solid  Gas
b) Boiling- Liquid  Gas
c) Melting- Solid  Liquid (Endothermic)
d) Freezing- Liquid  Solid (Exothermic)
e) Evaporation- Liquid  Gas
f) Condensation- Gas  Liquid
**Boiling is L  G its boiling point. Evaporation is L  G below the boiling point. **
**Condensation is clouds, when water vapor was form when gas cools down. **
**Sublimation (solid carbon-dry ice), doesn’t melt, skip liquid and form gas.
 The energy that is added during a change of state is used to break the attractions between particles. So, the temperature does not change until the change of state is complete.
 Understand about the lab we do on Boiling and freezing of water. (A Hot and Cool).

Chapter 3

1) Elements
 An elements is made up by atoms, is a pure substance, they can’t be separate, but they can combine to make other substance. They are the simplest substance, and it could be change both in physically and chemically.
 Different properties of elements
a) Metals: good conductors of heat and electricity, and they are shinny. Malleable, and also ductile.
b) Nonmetals: poor conductors of heat and electricity, and it tend to be brittle and unmalleable.
c) Metalloids: also called semi-conductors. They have properties both metals and nonmetals. Some are shiny, some are dull, and some metalloids are good conductors of heat and electric current as well.
2) Compounds
 A pure substance that is made up of elements.
 Substances are made up of combination of atoms are called molecules.
 The ratio of compound is always constant.
 In compound if you change the ratio of it, it will be totally different things.
 Compounds can be broken down into simpler substances only by chemical changes (apply heat or electric current).

3) Mixtures
 Two or more substances are put together physically, and can be separated physically.
 Ways to separate mixture:
a) Magnets
b) Filtering
c) Distillation (heating)
d) Separated by density (centrifuge)
 The ratio for mixture is not constant.
 Solution is a mixture that appears to be a single substance. A solute is dissolve in solvent. And the solution looks like the solvent, its appear if the solute is gone/
 Concentration: percentage of solute in a solvent.
a) Dilute: weak solution
b) Concentrated: strong solution
 As temperature increases, the solubility of solid in liquid increases, and the solubility of gas decrease.
 Heating, mixing, and crushing could help increases the solubility of a solid in liquid.
 Colloid is very similar to suspension but the particle ado not settles to the bottom. They are all over the place. (Ex. Jelly)
 Suspension the particle does not dissolve in solvent, but the particle is massive enough to settle to the bottom.
 Understand the lab about Flame test.

Chapter 4

1) Atomic Theory
 In 440 B.C. A Greek philosopher Democritus says that you can divide matter into certain point, after that you can not divide anymore. Atoms, which in Greek mean can not be divided.
 Dalton’s theory of the atom. Atomic theory:
a) All substances are made of atoms. Atoms are small particles that cannot be created, divided, or destroyed.
b) Atoms of the same element are exactly alike, and atoms of different elements are different.
c) Atoms join with other atoms to make new substances.
 Thomson’s prove that electrons exist. He found that negatively charged particle exists, and he called it “Electron”  Electricity.
a) Thomson’s models was the chocolate chips one, and he’s experiment is the one that almost all gas was removed from the glass tube.
 Rutherford proves that proton exists, gave a better general shape of atoms.
a) Rutherford he did “gold-foil experiment”, and the result is that there are some particles bounced straight back rather than passes straight through the gold foil.
 Neutron: no charge, cause proton/electron to move, mass (1 amu).
 Proton to establish # of proton in each element, look at atomic number. Proton gives elements positive charge, mass (1 amu), and its identity.
 Number of proton: atomic number
 Number of neutron: atomic mass(p+n) – atomic # (p) = # of neutron
 Isotopes are elements that are the same type of element but have different atomic masses. (Same # of proton, but different # of neutron)
a) Example of isotopes: H-2 (1 proton, 1 neutron), C-12 (6 protons, 6 neutrons), Si-29 (14 protons, 15 neutrons), etc.
 Forces in atom:
a) Gravitational force: a force that pull all object together. (As mass increase, gravity increase.)
b) Electromagnetic force: a force that repels same charges, and attract opposite charge. (P+,E- kept together with this force)
c) Strong force: this force is stronger than the electromagnetic force and keeps P+ inside the nucleus.

Chapter 5:

 Grouping the elements:
 Group 1 Alkali Metals (Famous known: Sodium, Potassium)
 It is extremely reactive, so reactive that they are not found alone in the nature.
 Group 2 Alkaline Earth Metals (Famous known: Calcium)
 Reactive but not as reactive as group one. Have 2 electrons in out shell, and give away the 2 electrons.
 Group 3-12 Transition Metals (Famous known: Silver, Copper)
 As you move from LR become less and less metallic, these can have 1, 2, or 1 or 2 electrons in the outer level.
 Group 13 Boron group (Famous known: Aluminum)
 3 electrons in the out level, gives out 3 electrons, somewhat reactive.
 Group 14 Carbon Group (Famous known: Carbon, Tin)
 4 electrons in the outer level, these elements share electrons, combine. Not reactive, because sharing and combining.
 Group 15 Nitrogen Group (Famous known: Nitrogen)
 5 electrons in the outer level, it will gain 3 electrons from metals, or share with other non-metal.

 Group 16 Oxygen Group (Famous known: Oxygen)
 6 electrons in the outer level, either gain 2 electrons from Metals, or share with other non-metal.
 Group 17 Halogens Group (Famous known: Chlorine, Iodine)
 7 electrons in the outer level, either gain 1 electron, or share. Extremely reactive
 Group 18 Noble Gases (Famous known: Argon)
 Not reactive, because they already have a full out level.
 Horizontal row of elements are called period, period also show the number of energy level (electron level).
 Vertical column of elements are called group or family, group also show the number of electrons in the outer most level.