Topic 2 Changes in Matter Changes in matter

  • Slides: 5
Download presentation
Topic 2: Changes in Matter Changes in matter can be classified two ways: 1.

Topic 2: Changes in Matter Changes in matter can be classified two ways: 1. Physical Change • The substance changes form/state, but no new substances are formed. e. g. liquid to solid, solid to liquid, liquid to gas etc. 2. Chemical Change • One or more new substances are formed. The reaction is difficult if not impossible to reverse. e. g acid dissolving metal to produce a gas, wood burning to produce smoke and ash.

Rules to determining if a change is chemical or physical: • Heat is produced/absorbed.

Rules to determining if a change is chemical or physical: • Heat is produced/absorbed. • Starting material/chemicals is used up. • Colour change • Material/chemical with new properties is formed. • Gas bubbles form in a liquid. • A precipitate, (solid particles), form in a liquid. • The change is difficult/impossible to reverse. *** If two or more of the above are observed the change is likely chemical. *** Physical Properties • Any property that can be observed or measured without a new substance being formed. Examples: appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity, etc.

Physical Properties • Any property that can be observed or measured without a new

Physical Properties • Any property that can be observed or measured without a new substance being formed. Examples: appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity, etc. • They are classified as qualitative and quantitative. Qualitative: is a property that can be described not measured with numbers. (Colour) Quantitative: is a property that must be measured with numbers. (Melting point)

 • Chemical Properties • Properties that describe how a substance reacts with another

• Chemical Properties • Properties that describe how a substance reacts with another substance when forming a new substance. • Examples: reacts with water, reacts with oxygen, reacts with pure substance, stability, combustibility, etc. http: //www. youtube. com/watch? v=-Ypwtjp 0 FSE