CHEMISTRY
What is Matter?
• Matter- anything that has mass and takes up space.
• Mass- the measure of the amount of matter in an object.
• Substance- a particular kind of matter.
• Element- a substance that cannot be changed into simpler substances by ordinary means.
• Compound- a substance that is made up of 2 or more elements chemically combined.
• Mixture- a combination of 2 or more kinds of matter that can be separated by physical means.
States of Matter
• Solid- Any substance with a definite shape and a definite volume.
• Liquid- Any substance that has a definite volume but no definite shape.
• Gas- Any substance that has neither a definite shape nor a definite volume.
• Plasma- A cloud of electrically charged particles.
• How do solids become liquids? Become gasses?
The molecules vibrate faster as the temperature goes up, causing the substance to lose its shape and then its volume as well. This happens because the distance between the molecules increases as they bounce off of each other at faster rates of speed.
Physical changes & Chemical Changes
• Physical change- A change where the appearance of matter is different but the chemical make-up remains the same.
• Chemical change- A change that produces two or more kinds of matter that were not present before the change.
CORROSION- RUSTING
Properties of Matter
• Chemical property- The ability of a substance to undergo or resist chemical change.
• Physical property- Characteristics of matter that can be studied without changing its chemical make-up.
• Properties of liquids:
• Viscosity- The ability to flow and the extent to which a liquid does.
• Surface tension- A skin on the surface of a liquid.
• Cohesion- the force of attraction between similar particles.
• Adhesion- the force of attraction between unlike particles.
• Properties of solids:
• Elasticity- the ability to stretch out and then snap back into place.
• Malleability- The ability to be pounded into thin sheets.
• Brittleness- the extent to which a substance will shatter.
• Ductility- The ability to be pulled into thin wire.
Changes of State
• Melting point- The temp. where a solid becomes a liquid.
• Freezing point- The temp. where a liquid becomes a solid.
• Boiling point- The temp. where a liquid becomes a gas.
• Condensation point- The temp. where a gas becomes a liquid.
• Sublimation- When a solid appears to go directly to the gas state.
The Periodic Table
• Atomic Number- The number of protons in the nucleus of an atom.
• Atomic Symbol- The Latin abbreviation of the name of an element.
• Atomic Mass- The average mass of an atom of any particular element. It can also be found by adding the protons and the neutrons of an element.
Structure
• Non-Metals- do not conduct electricity very well, very brittle, not malleable or ductile.
• Metalloids- Have properties of metals and of non-metals- found along the stairstep - Al is only exception.
• Metals- Good conductors of heat and electricity, malleable, ductile, and have a metallic luster.
• Period- Horizontal rows of elements whose # is equal to the number of shells the atom has.
• Family- Vertical columns on the periodic table consisting of elements with similar chemical properties and also sometimes corresponding to the number of valence electrons.
Families
• IA- Alkali Family- do not occur freely in nature- 1e- in outer shell.
• IIA- Alkaline Earth Family- rarely do they occur freely in nature- 2e- in outer shell.
• VIIA- Halogens- “salt-maker”- 7e- in outer shell.
• VIIIA- Inert or Noble gases- Stable e- configuration.
• B- Transitions Metals- all metals- Fe, Co, & Ni are only magnetic elements- variable outer shell e-.
Density and Specific Gravity
• D=m/V density=mass/ Volume
• Specific gravity= density of a substance/ density of H2O ( 1.0 g/ml )