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8/3/2019 Science LT1 Is

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Properties of Matter

Chemical Properties

Reactivity- ability to readily interact chemically with other substances

- ex: rusting, giving off odors, changing color, new substance formed, formation of gas/fumes orprecipitate, absorption/release of heat

Flamability- ability to produce a flame

Physical Properties

Density- amount of matter in the volume of a substance- intensive property

Melting Point- the temp. at which a solid turns into a liquid- intensive property

Boiling Point- the temp. at which a liquid turns into a gas- intensive property

Thermal and Electrical Conductivity- metals with high conductivity are conductors, those with low conductivity are insulators

Malleability- the ability to be morphed without breaking/flattened into thins sheets

Ductility- the ability to be stretched into wires or threads- intensive property

Intensive Properties

- dont depend on the size/amount of the substance

- Boiling Point, Melting Point, Density, Taste, Color, Luster, Ductility

Extensive Properties- depends on the size/amount of the substance

- Mass, volume, length

Separation Techniques

Physical manipulation- manually separating/sorting- Ex: Separating iron nails and screws


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Filtration- use of a filtering material that will let only same components through

Decantation- separating of the components that form distinct layers (immiscible)- Ex: Pouring one layer out of an oil+water mixture

Simple Distillation- components are separated due to the differences in their boiling points- let water evaporate then let it condense

Fractional Distillation- special process used for the preparation of fuel and other petroleum products

Evaporation- involves heating the mixture to separate the solid residue from the liquid- to get the solute from a solution

Use of Magnet

Paper Chromatography

Changes in Matter

Physical Change

- the molecules of the material undergoing physical change retain their identity. No new substance is

formed. The change is only in SIZE, SHAPE, or PHASE of the material

Chemical Change

- the molecules of the substance involved in a chemical reaction change their identity because a.) the

atoms that constitute the molecules may be rearranged, b.) atoms may be removed from the

molecule, or c.) atoms may be added to those in the molecule. Hence, a new substance or substances

are formed, but the atoms RETAIN their identity.

Atomic Models and Scientists

Democritus- came up with the word atom or atomos, which means indivisible in Greek- proposed that: Atoms can be in any shape

Atoms are infinite and constantly movingAtoms can combine with other atomsAtoms are indivisible


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John Dalton

- first atomic theory:

1. Matter is composed of tiny indivisible particles called atoms.2. Atoms of a particular element are identical.

3. Atoms of different elements have different masses.4. Atoms of different elements can join to form compounds.

J.J Thompson

- discovered the electron- concluded that there must be particles within the atom even without confirmation of theirexistence

- proposed the plum pudding model> atoms contain smaller sub-atomic particles (Trivia: Quarks)

Ernest Rutherford

- discovered the nucleus> protons> called the area, nucleus

> the atom is mostly empty space> the nucleus may be tiny, but contains 99.99% of the atoms mass

Niels Bohr

- came up with the planetary model of the atom> each electron in an atom has a fixed amount of energy> energy keeps an electron moving around the nucleus within a specific regioncalled energy levels

James Chadwick


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- discovered the neutron> nucleus contains neutrons> neutrons have same mass as protons but neutrons have no electrical charge> electrons move constantly around the nucleus

Erwin Schrdinger

- came up with the quantum mechanical model of theatom/Electron Cloud model

Heisenberg

- contributed to Schrodingers work

Atomic Anatomy

- an atom has 3 basic particles: 1. Proton (nucleus), 2. Neutron (nucleus), and 3. Electron (outside thenucleus)

- atomic number = # of protons = * # of electrons (* if atom is neutral)

- most atoms are neutral (+ = -), but some atoms gain or lose an electron. When this happens, the atom

becomes charged; ION

Ex: Fluorine atom + 1 electron F-

Sodium atom 1 electron Na +

- mass number = # of protons + # of neutrons

- # of neutrons = Mass number Atomic number

Element Atomic # Mass # # of Protons # of Electrons # of Neutrons

Hydrogen 1 1 1 1 0

Carbon 6 12 6 6 6

Oxygen 8 16 8 8 8

Sources: Textbook, and powerpoints

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