AP Bio Chap. 2 Flashcards
(30 cards)
Atoms
Particles that are the building blocks of all substances.
Protons
Inside an atom’s central core, positive charge.
Neutrons
Inside an atom’s central core, no charge.
Elections
Inside an atom, circling the core, negative charge.
Nucleus
Atom’s central core.
Atomic Number
The number of protons, determines that element.
Element
Pure substances, each consisting only of atoms with the same number of protons.
Mass Number
Total number of protons and neutrons in their nucleus.
Periodic Table
Arrangement of elements based on their chemical properties.
Radioisotopes
Radioactive isotopes.
Radioactive Decay
Can transform one element into another.
Tracer
Any molecule with a detectable substance attached.
Electonegativity
A measure of an atom’s ability to pull electrons from other atoms.
Chemical Bond
An attractive force that arises between two atoms when their electrons interact.
Molecule
Forms when two or more atoms of the same or different elements join in chemical bonds.
Compounds
Molecules that consist of two or more different elements in proportions that do not vary.
Mixture
Two or more substances intermingle and their proportions can vary because the substances do not bond with each other.
Ionic Bond
A strong mutual attraction of two oppositely charged ions.
Covalent Bond
Two atoms share a pair of electrons.
Nonpolar
The atoms participating in the bond are sharing electrons equally.
Polar
Bonds that do not share electrons equally.
Polarity
Any separation of charge into distinct positive and negative regions.
Hydrogen Bond
Weak attraction between a highly electronegative atom and a hydrogen atom taking part in a separate polar covalent bond.
Solvent
Substance, usually liquid, that can dissolve other substances.
