Properties of Matter and Changes Quiz

Properties of Matter

• Physical and chemical properties are useful for identifying substances.
• A physical property can be observed without changing the substance's composition (e.g., color, density).
• A chemical property describes how a substance reacts with other substances (e.g., flammability, reactivity with water).
• Examples of physical properties (not discussed): melting point, boiling point, solubility, conductivity.

Physical and Chemical Changes

• A physical change alters a substance's appearance but does not change its chemical composition.
• A chemical change transforms a substance into a new substance with different properties.
• Clues for chemical changes: color change, formation of a gas or precipitate, change in temperature, odor, light production.
• Examples of physical changes: melting ice, dissolving sugar in water, freezing water, cutting paper.
• Examples of chemical changes: burning wood, rusting iron, baking a cake, tarnishing silver.

WHMIS and Lab Safety

• MSDS (Material Safety Data Sheet) provides information about hazards associated with chemicals.
• WHMIS (Workplace Hazardous Materials Information System) is a system for classifying and labelling hazardous materials.
• Importance of WHMIS and MSDS: ensuring safe handling and use of chemicals, preventing accidents.

Atoms and Bohr-Rutherford Diagrams

• Bohr-Rutherford diagrams show the structure of atoms (nucleus with protons and neutrons, electrons in energy levels).
• Information contained in a Bohr-Rutherford diagram: number of protons, neutrons and electrons.
• The nucleus of one element cannot be exactly the same as a nucleus of a different element (different number of protons)
• Electrons are found orbiting the nucleus in different energy levels.

Periodic Table Patterns

• The periodic table provides information to predict the number of electrons in an atom's outermost shell.
• Metals typically have fewer outermost electrons than nonmetals.
• The periodic table helps identify elements in different ways. (Example: Halogens in the second period, alkali metals in the fifth period).
• The number of outermost electrons varies across a period and down a group

Periodic Trends and Ions

• Some elements naturally exist as diatomic molecules.
• Anion: negatively charged ion (gained electrons)
• Cation: positively charged ion (lost electrons)
• Atoms or ions that have the same number of electrons;
• Ions with specific electron counts are not always stable.
• Ions are formed when atoms gain or lose electrons to achieve a stable outer electron shell.
• Ionic bonds involve the electrostatic attraction between oppositely charged ions.
• Full outer electron shells are energetically favorable (more stable)

Ionic Compounds

• Ionic compounds are formed by the combination of metals and nonmetals.
• Nonmetals are not likely to form ionic bonds together because they both need to gain electrons to be stable.
• Ionic compounds dissolve in water to form ions in specific ratios. Example: NaF dissolves in water to form Na+ and F- ions
• Transition metals require special naming conventions for their compounds, to differentiate the charge possibilities of the metal.

Naming Molecular Compounds

• Molecular compounds are formed from nonmetals.
• The naming conventions for molecular compounds differ from those for ionic compounds.
• Naming molecular compounds involves identifying the elements and using prefixes to indicate the number of atoms of each element.
• Example: CO (carbon monoxide), PF5, PCl3, OCl2 (carbon dioxide).

Chemical Reactions

• Chemical equations show reactants and products involved in a reaction using chemical formulas.
• The arrow signifies a chemical change.
• The Law of Conservation of Mass states mass is conserved in a chemical reaction.
• (aq) indicates that a substance is dissolved in water.

Acids and Bases

• Acids: characteristic properties (e.g. Sour taste, react with metals, corrode).
• Bases: characteristic properties (e.g. bitter taste, slippery feel, react with acids).
• pH scale measures acidity and basicity of a solution.
• Neutralization occurs when an acid reacts with a base to form salt and water.

pH Scale

• Neutralization: a chemical reaction between an acid and a base that forms a neutral product (salt and water).
• pH scale measures acidity and basicity: the pH of a solution is 7 is neutral; pH values above 7 are basic; pH values below 7 are acidic,
• Different substances have different pH's. 
• pH values help identify the degree of acidity and basicity of various substances.

pH in the Environment

• Soil pH is important for agricultural purposes.
• Acid leaching is a cause of environmental damage.
• Acid precipitation harms the environment.
• Acid precipitation is formed by compounds like SO2 and NO.
• Acid precipitation has many impacts, like affecting the economy, and harming the environment.
• Solutions to prevent acid precipitation are needed for environmental sustainability.

Test your knowledge on the physical and chemical properties of matter, and differentiate between physical and chemical changes. Explore examples and clues for identifying changes in substances. Perfect for reinforcing your understanding of these fundamental concepts!