Text Chapter 2: Atoms, Molecules, and Water Flashcards Preview

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Flashcards in Text Chapter 2: Atoms, Molecules, and Water Deck (20):
1

Element

substance that cannot be broken down to another substance with different properties

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Atom

smallest unit that has characteristic properties of the element

3

Molecule

Two or more atoms joined by chemical bonds

4

Composition of an Atom

Nucleus: protons, neutrons
Each electron circles the nucleus in an orbit representing a specific energy level

5

Atomic Number

number of protons

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Atomic Mass

number of protons+ number of neutrons

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Electron Distribution

Energy Level 1: 2 electrons
Energy Level 2: 8 electrons
Energy Level 3: 8 electrons

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Electron

negatively charged particle (number of electrons=number of protons)

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Proton

positively charged particle (number of protons equal number of electrons)

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Cohesion

the ability of water molecules to bond to each other

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Adhesion

water molecules associate with other (non-water) molecules or surfaces

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Ionic Bond

one atom loses an electron, another gains an electron *strongest bond

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Covalent Bond

atoms share electrons

14

Polar-Covalent Bond

atoms share electrons unequally

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Hydrogen Bond

covalently bound hydrogen is attracted to another atom *weakest bond

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Due to Hydrogen Bonding, Water shows:

surface tension (cohesion), capillary action (adhesion), resists temperature change

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According to the pH scale:

Acidic is closest to 0, pH+>pOH-
Neutral= 7, pH+=pOH-
Basic is closest to 14, pOH->pH+

18

Water has High Values for

specific heat, heat of vaporization

19

Specific Heat

heat needed to change temperature

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Heat of Vaporization

heat needed to convert liquid to gas