• Orientation of Human Anatomy
• Cardiovascular System
• Respiratory System
• Nervous System
• Digestive System
• Skeletal System
• Muscular System
• Endocrine System
• Immune System
• Integumentary System
• Urinary System
• Reproductive System

• The Cell
• Macromolecules
• Cell Division
• DNA, RNA & Genetics
• Classification & Microorganisms

• Atomic Structure
• Chemical Bonds
• States of Matter
• Solutions, Acids and Bases
• Chemical Reactions

• The Scientific Method
• Variables
• Hypotheses, Theories & Laws
• Reliability & Validity
• Interpreting Data
• Measurement & Tools

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TEAS® Science Study Guide

Chemical Bonds

Atoms bond to fill their outer electron shells. Two main types:

• Ionic bond — One atom transfers electrons to another. Forms between a metal and a nonmetal. The atoms become oppositely charged ions and attract. Example: sodium chloride (NaCl), table salt.
• Covalent bond — Atoms share electrons. Forms between nonmetals. Example: water (H₂O).

A quick test: metal + nonmetal usually means ionic; nonmetal + nonmetal usually means covalent.

Terms to know

• Ionic bond — Electrons transferred; metal + nonmetal.
• Covalent bond — Electrons shared; nonmetal + nonmetal.
• Cation — Positive ion. Anion — Negative ion.
• Molecule — Two or more atoms bonded together.

What the TEAS asks most

• Which bond transfers electrons? Ionic.
• Which bond shares electrons? Covalent.
• What kind of bond is NaCl? Ionic.
• What’s a positive ion called? Cation.

Chemical Bonds Review Quiz