Properties of Matter Quiz

Properties of Matter

• Matter is anything that has mass and takes up space
• All matter is made of particles
• The type and arrangement of particles determine the matter's properties
• Most matter exists as solids, liquids, or gases

Measuring Matter

• Volume: The space an object occupies. Measured by calculating length x width x height or in milliliters (mL) using a graduated cylinder.
• Mass: The amount of matter in an object. Measured using a triple-beam balance or an electronic balance.
• Weight: The force of gravity acting on an object's mass. Expressed in newtons, but mass is expressed in kilograms. Weight can change depending on gravity, but mass remains constant.

Physical Properties

• Physical property: A characteristic of a substance that doesn't involve a chemical change.
• Examples include: density, color, state of matter (solid, liquid, gas), hardness, melting point, and boiling point.
• Changing the state of a substance (e.g., ice to water) is a physical change; the substance's identity remains the same.

Chemical Properties

• Chemical property: A characteristic of a substance that describes its ability to participate in chemical reactions.
• Chemical properties can only be determined by trying to cause a chemical change in the substance.
• For example, burning paper changes its composition and turns it into a new substance.

Evidence of Chemical Changes

• Formation of a precipitate: A solid forming in a liquid.
• Evolution of a gas: Production of a gas, often observed as bubbling.
• Color change: Color changes within a reaction system.
• Release or absorption of energy: Energy can be either released or absorbed during a chemical change.

Reactants vs. Products

• Reactants: Substances on the left side of a chemical equation.
• Products: Substances on the right side of a chemical equation.

Every Change in Matter Involves a Change in Energy

• All physical and chemical changes involve a change in energy.
• Energy is the ability to do work.
• Sometimes energy is needed to start a change, other times energy is released.

Changing States of Matter

• Ice melting and water boiling are examples of physical changes.
• A physical change only affects the physical properties of a substance; the substance's identity remains the same.

Pure Substances/Elements

• All matter is composed of about 110 different kinds of atoms.
• Atoms can be physically mixed or chemically combined to form all kinds of matter.
• Elements consist of only one type of atom.

Pure Substances

• A pure substance is a sample of matter that is either a single element or a single compound.
• Pure substances have definite chemical and physical properties.

Elements are Pure Substances

• Elements contain only one type of atom.
• Some elements exist as single atoms (e.g., helium).
• Other elements exist as molecules.

Elements as Single Atoms or as Molecules

• A molecule is the smallest unit of a substance that keeps all of the physical and chemical properties of that substance; it consists of one or more atoms bonded together.

Compounds

• Compounds are pure substances made of more than one kind of atom.
• Compounds are represented by formulas showing the ratio of atoms.

Mixtures

• A mixture is a sample of matter containing two or more pure substances.
• Many kinds of food are mixtures (excluding sugar and salt).
• Water is not a mixture; hydrogen and oxygen atoms are bonded to form a molecule.

Mixtures can Vary in Composition and Properties

• Mixtures don't always have the same proportions of ingredients.
• This leads to variations in their properties.

Homogeneous vs. Heterogeneous Mixtures

• Homogeneous mixture: A mixture with a uniform distribution of materials throughout. Examples include sweetened tea and 14-karat gold.
• Heterogeneous mixture: A mixture with dissimilar components not evenly distributed. Examples include sand and water or a salad.

Classification of Matter

• Matter can be classified into pure substances (elements and compounds) and mixtures (homogeneous and heterogeneous).

Classification of Matter—Review

• Matter is anything that has mass and takes up space.
• A molecule is a particle made of two or more atoms bonded together.
• Mixtures contain two or more different types of particles.

Review (Questions)

• Your friend eats only natural foods to avoid chemicals; what are the issues with this?
• Is toasting bread a physical or chemical change, and why?
• Classify the following as physical or chemical changes, explaining why:
  • Cracking an egg
  • Using bleach to remove a stain
  • Burning a candle
  • Melting butter in the sun