States of Matter 3.1 Four Phases of Matter: solid liquid gas plasma

Solids  Particles of solids are tightly packed, vibrating about a fixed position.  Solids have a definite shape and a definite volume.  Crystalline solids – molecules are arranged in a geometric pattern (ex. Table salt)  Amorphous solids – molecules do not have a set pattern of arrangement (ex. Gels)

Liquids  Particles of liquids are tightly packed, but are far enough apart to slide over one another.  Liquids have an indefinite shape and a definite volume.

Gases  Particles of gases are very far apart and move freely.  Gases have an indefinite shape and an indefinite volume.

Plasma  A plasma is an ionized gas.  A plasma is a very good conductor of electricity and is affected by magnetic fields.  Plasma, like gases have an indefinite shape and an indefinite volume.

Comparing States of Matter DefiniteVolumeDefiniteShape SolidYesYes LiquidYesNo GasNoNo PlasmaNoNo

3.2 Notes For a phase change, the energy added to or removed from a substance comes from the surroundings (such as the air, its container, a stove, etc.).

3.2 Notes melting: when energy is added to a solid substance so it becomes a liquid freezing: when energy is removed from a liquid substance so it becomes a solid

3.2 Notes boiling: when energy is added to a liquid substance so it becomes a gas condensing: when energy is removed from a gas substance so it becomes a liquid

3.2 Notes sublimation: when a solid substance becomes a gas without ever being a liquid –Example: dry ice (carbon dioxide) –Example: ice cubes in a frost free freezer get smaller

3.2 Notes evaporation: when a liquid substance becomes a gas without having any extra energy added –Because the gas floats away with energy, the rest of the substance left behind becomes cooler.

3.2 Notes Temperature is constant during changes of state. Example: If you add energy to ice at 0 ºC, the temperature will not rise until all the ice has melted. Why? Because all the energy goes to breaking the ice bonds to make it water first.

3.2 Notes What do you notice about the red parts of the graph? What does that mean?

3.2 Notes Conservation of Mass & Energy: Mass and energy are conserved in chemical and physical changes. Mass and energy cannot be created or destroyed It can be changed or transferred It never changes in total amount

3.2 Notes Mass Example Burning match: The match seems to lose mass. However, if you collected the smoke and gas produced while burning, then all the mass would be there. Energy Example Lawn Mower has chemical energy in the gasoline. That energy is turned into kinetic energy to move the mower as well as waste heat as the engine gets hot. This energy should equal the chemical energy of the gasoline used up.

Atoms Ch. 4 Matter is anything that takes up space and has mass. All matter is made of atoms Atoms are the building blocks of matter, sort of how bricks are the building blocks of houses.

An atom refresher An atom has three parts: Proton = positive Neutron = no charge Electron = negative The proton & neutron are found in the center of the atom, a place called the nucleus. The electrons orbit the nucleus.

Isotope = same element with a different number of neutrons –Mass number – protons = neutrons

Electrons have special rules…. You can’t just shove all of the electrons into the first orbit of an electron. Electrons live in something called shells or energy levels. Only so many can be in any certain shell. Valence electrons are in outermost shell.

So let’s try it…. 3 Li Lithium Protons = 3 Neutrons = 4 (7-3=4) Electrons = 3 2 in the 1 st shell, 1 in the 2 nd shell

What are elements? Elements are the building blocks of all matter. Elements are made of atoms. While the atoms may have different weights and organization, they are all built in the same way. The periodic table is a list of all of the elements that can build matter. It’s a little like the alphabet of chemistry.

Created by G.Baker Periodic Table 8 O Oxygen 16 Atomic Number: Number of protons and it is also the number of electrons in an atom of an element. Element’s Symbol: An abbreviation for the element. Elements Name Atomic Mass/Weight: Number of protons + neutrons.