Chemistry 2e - Chapter 1

The properties of matter can be classified as physical and chemical. Density, hardness, color, melting point, and boiling point are all physical properties. Chemical properties include flammability, toxicity, reactivity, and acidity. Physical properties can be observed and measured without changing the identity of the substance. Chemical properties are observed and measured when a chemical reaction occurs.

A physical change involves a change in the state or appearance of matter. A list of activities that produce a physical change is displayed below. When matter undergoes a chemical change, one or more of the observations listed (below right) will occur.

Physical Change
Cutting
Mixing
Dissolving
Heating
Melting
Freezing
Evaporation

Chemical Change
Temperature changes
Color changes
Gas forms (bubbles) / Odor
Precipitate forms
Light is produced
Taste changes (only test
if you are a food chemist)

Activity: complete the TRQ 1.3a: Physical and Chemical Changes assignment. Predict whether an observed change in a compound is physical or chemical.

The Classification of Matter - matter is classified as an element, compound, homogeneous mixture or heterogeneous mixture.

Is the sample of matter a pure substance?

if yes, is it an element (one of the "squares" on the Periodic Table below) or a compound (a collection of elements)?
if no, does it have the same consistency throughout (homogeneous) or does it possess variations and inconsistencies (heterogeneous)?

Activity: classify each sample of matter listed below as either an element, compound, homogeneous mixture, or heterogeneous mixture. Click each of the 22 samples of matter to check your answer.

Activity: complete the Timed Repetitive Quiz (TRQ) Sets TRQ 1.3b: Matter and Density assignment to gain experience in classifying a sample of matter as a homogeneous mixture, a heterogeneous mixture, a compound or an element.

Sherlock Holmes
British detective

"It's Elemental My Dear Watson" - the Periodic Table contains the building blocks of nature . . . . elements. Every known molecule has been "assembled" from 118 elements. The interactive Periodic Table below displays a wealth of information about each element.

Physical Properties - mouse over an element to display a list of physical properties you may need while studying Chemistry.
Atomic Mass Unit (amu) Calculator - determine the atomic mass of an element or molecule. The atomic mass of carbon dioxide is calculated by clicking on Carbon once and Oxygen twice. One molecule of CO₂ has an atomic mass of 44.01 amu.
Molar Mass Calculator - determine the molar mass of a molecule. The molar mass of water is calculated by clicking on Hydrogen twice and Oxygen once. One mole of H₂O has a mass of 18.015 g.

Activity: use the interactive Periodic Table to find the following information. Once you have written down an answer, click Show Answer to check your answer.

Density Copper 8.96 g/mL Show Answer	Boiling Point Bromine 59°C Show Answer	Atomic Mass Carbon 12.011 amu Show Answer	Radius Aluminum atom 143 pm Show Answer	Melting Point Mercury -39°C Show Answer

Electronegativity of Fluorine 3.98 Show Answer	Molar Mass Water (H₂O) 18.015 g/mole Show Answer	Molar Mass Oxygen (O₂) 31.999 g/mole Show Answer	Molar Mass Nitrogen (N₂) 28.013 g/mole Show Answer	Molar Mass CO₂ 44.01 g/mole Show Answer