ATI TEAS Version 7 Chemistry Guide

Overview

• The science portion of the ATI TEAS test consists of 44 questions, with 8 dedicated to chemistry.
• Key topics include:
  • Basic atomic structure
  • Physical properties and changes of matter
  • Chemical reactions
  • Properties of solutions
  • Acids and bases

Atomic Structure

• Atoms:

  • Consist of protons (positive charge), neutrons (neutral charge), and electrons (negative charge)
  • Atomic mass = protons + neutrons (electrons are negligible)
  • Isotopes have the same number of protons but different numbers of neutrons

• Atomic Number:

  • The number of protons in an atom
  • Determines the element's identity

• Ions:

  • Atoms that have gained or lost electrons
  • Cations: Positively charged (more protons)
  • Anions: Negatively charged (more electrons)

Periodic Table

• Elements organized by increasing atomic number
• Groups: Vertical columns
• Periods: Horizontal rows
• Special Elements:
  • Alkali/Alkaline earth metals (active metals)
  • Transition metals
  • Noble gases (inactive gases)

Orbitals and Electron Configuration

• Orbitals:

  • Regions where electrons are likely found
  • Types: s (2 electrons), p (6), d (10), f (14)
  • Order of filling: s, p, d, f

• Valence Electrons:

  • Electrons in the outermost shell
  • Determine element stability and reactivity

Chemical Bonds

• Ionic Bonds:

  • Formed by the transfer of electrons
  • Typically between metals and nonmetals

• Covalent Bonds:

  • Formed by sharing electrons
  • Typically between nonmetals

• Electronegativity:

  • Measure of an atom's attraction for electrons
  • Determines bond type

Physical Properties of Matter

• Mass: Amount of matter
• Volume: Space occupied
• Density: Mass per unit volume
• States of Matter: Solid, liquid, gas, plasma
  • Determined by temperature and pressure

Chemical Properties and Reactions

• Chemical Reactions:

  • Represented by chemical equations
  • Reactants -> Products
  • Example: Combustion reactions involve oxygen to form CO2 and H2O.

• Balancing Equations:

  • Ensure equal numbers of each type of atom on both sides

• Moles:

  • Measure the amount of substance
  • Important for reaction calculations

Reaction Rates and Equilibrium

• Factors Affecting Reaction Rates:

  • Catalysts: Lower activation energy
  • Temperature: Higher temperatures increase rates
  • Concentration: Affects collision rates

• Equilibrium:

  • Forward and reverse reaction rates are equal
  • Dynamic: Continuous but balanced changes
  • Static: No changes

Solutions and Solubility

• Water Polarity:

  • Water's polar nature leads to cohesion and adhesion
  • Solvent for dissolving solutes

• Concentration:

  • Measured in moles per liter (molarity)
  • Dilution involves adding solvent

Osmosis and Diffusion

• Osmosis:

  • Water movement through a semi-permeable membrane

• Diffusion:

  • Movement of molecules from high to low concentration

Acids, Bases, and Buffers

• Acids: Increase H+ ions

• Bases: Decrease H+ ions

• pH Scale: 0 (acidic) to 14 (basic), 7 is neutral

• Buffers: Resist changes in pH

  • Example: Blood buffer system

• Neutralization Reactions:

  • Acids and bases react to form water and salt

Conclusion

• The chemistry portion of the ATI TEAS is comprehensive. Understanding these concepts is crucial for doing well on the test.

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