Matter Chapter 2 notes

Definitions Matter- anything that has mass and occupies volume Intensive vs. Extensive Properties – Extensive properties depend on the amount. Mass and volume are the ONLY extensive properties you will be expected to know. – Intensive properties include everything else. Longer list to come

Intensive properties Intensive properties – properties that depend on the TYPE of matter NOT the AMOUNT of matter. This includes all physical and chemical properties.

Physical properties Physical property – something that can be observed about a substance WITHOUT changing the substance – Melting/freezing point – Boiling point – Color – Conductivity (can it conduct heat/electricity) – Hardness – Malleability (bendyness)

Physical properties Physical properties also dictate physical changes. Water, along with most other substances, can exist as a solid (ice), liquid (water), or a gas (steam or vapor). Physical properties govern what state of matter the substance will assume at a given temperature and pressure

States of matter State of matterShapeVolume SolidDefinite LiquidVariableDefinite Gas/vaporVariable

Phase change (don’t need to copy)

Chemical properties In addition to physical properties, intensive properties also include chemical properties. Chemical properties determine the ability of a substance to react with or become a different substance. Examples to come.

Chemical changes Examples of chemical changes include: – Burning/exploding – Rotting/fermenting – Rusting/corroding – Decomposing Chemical changes are expressed in chemical reactions.

Chemical substances Substances are either compounds or elements. Compounds are a combination of two or more elements – H 2 O, CO 2 (NH 4 ) 2 SO 4, etc. Elements contain only one element – Li, Fe, O 2, C, C 60, O 3, S 8, P 4, etc.

Chemical reactions Compounds can only be separated into their elements by chemical reactions. For example water, H 2 O, can be separated into hydrogen and oxygen using a battery. Chemical reaction 2 H 2 O (l)  2 H 2(g) + O 2(g) Physical reaction H 2 O (l)  H 2 O (g)

Symbols vs. Formulas A chemical formula is made up of atomic symbols. – H is hydrogen – He is helium All atomic symbols begin with a CAPITAL letter. Some are followed by lower case, but not all.

Symbols vs. Formulas A chemical formula is simply a combination of two or more atoms H 2 O is a chemical formula H 2 is also a chemical formula even though it doesn’t have two different elements. The little two means that you have two hydrogens.