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atoms & the particles: electron, neutron, proton - charge and location and amount in an element

• classify elements, compounds, mixtures (homogeneous vs. heterogeneous)

• solutions, solubility, concentration

• density, mass, volume

• different states of matter (solid, liquid, gas)

• changes in states of matter (melting/freezing; evaporation/condensation)

Atoms & Particles

  • Atoms: The basic units of matter consisting of subatomic particles.

    • Electrons: Negatively charged particles found in electron clouds surrounding the nucleus.

    • Neutrons: Neutral particles found in the nucleus of the atom.

    • Protons: Positively charged particles found in the nucleus.

    • The number of protons determines the atomic number and the element's identity.

Classifying Matter

  • Elements: Pure substances that cannot be broken down into simpler substances.

  • Compounds: Substances formed when two or more elements chemically bond together.

  • Mixtures: Composed of two or more substances that are physically combined.

    • Homogeneous: Uniform mixtures (e.g., saltwater).

    • Heterogeneous: Non-uniform mixtures (e.g., salad).

Solutions, Solubility, & Concentration

  • Solutions: Homogeneous mixtures where one substance (solvent) dissolves another (solute).

  • Solubility: The ability of a substance to dissolve in a solvent.

  • Concentration: The amount of solute in a given volume of solvent, often expressed in molarity (moles per liter).

Density, Mass, & Volume

  • Density: Measure of mass per unit volume (density = mass/volume).

  • Mass: The amount of matter in an object, typically measured in grams or kilograms.

  • Volume: The amount of space an object occupies, typically measured in liters or cubic centimeters.

States of Matter

  • Solid: Defined shape and volume with closely packed particles.

  • Liquid: Defined volume but takes the shape of its container with particles that are close but can flow.

  • Gas: No defined shape or volume; particles are far apart and move freely.

Changes in States of Matter

  • Melting/Freezing: Transition between solid and liquid states.

  • Evaporation/Condensation: Transition between liquid and gas states.