Biology- Unit 2A: Chemistry of Life (Atomic Structure and Bonds, Properties of Water, and pH and Buffers)

Atom

The smallest unit of matter.

Covalent Bond

The type of bond formed when two atoms share a pair of electrons.

Proton

The particle in the nucleus of an atom that carries a positive charge.

Neutron

The particle in the nucleus of an atom that carries no charge.

Atomic Mass

Indicates the number of protons plus the number of neutrons in an atom.

Electron

The particle that moves around the nucleus of an atom and carries a negative charge.

Ionic Bond

The type of bond formed through electrical attraction between oppositely charged ions.

Ion

An atom that has gained or lost one or more electrons.

Atomic Number

This indicates the number of protons in an atom.

Valence Electrons

The electrons in the outermost energy level of an atom.

CaCl₂ is a __ bond.

Ionic - metal + nonmetal

K₂SO₄ is a __ bond.

Ionic - metal + nonmetal

ZnO is a __ bond.

Ionic - metal + nonmetal

C₆ H₁₄ is a __ bond.

Covalent - nonmetal + nonmetal

CH₄ is a __ bond.

Covalent - nonmetal + nonmetal

CH₃COCH₃ is a __ bond.

Covalent - nonmetal + nonmetal

Imbibition

Allows seeds to grow in order for plants to grow and develop.

Cohesion

Allows water to join with other water molecules.

Adhesion

Allows water to join with other substances.

Capillary Action

Allows plants to obtain the necessary water for photosynthesis from its roots to its leaves.

Surface Tension

Allows organisms, like water striders (insects) to walk on water.

Universal Solvent

Allows nutrients to dissolve in water so organisms can obtain them.

High Heat Capacity

Allows organisms that live in the water a constant living environment.

Acid

An __ is a compound that contains more H+ ions in a solution.

Buffer

A __ is a substance that resists changes in pH.

Base

A __ is a compound that contains more OH- ions in a solution.

Neutral

A __ solution contains equal concentrations of H+ and OH- ions.

A solution with a pH of __ would be considered neutral (0-6.99; 7; or 7.01-14)

7

A solution with a pH of __ would be considered an acid (0-6.99; 7; or 7.01-14)

0-6.99

A solution with a pH of __ would be considered a base (0-6.99; 7; or 7.01-14)

7.01-14

Where are the acids located on this scale?

A

Where is the neutral located on this scale?

B

Where are the bases located on this scale?

C

Which side has the MOST H+ ions and the LEAST OH- ions?

Acidic Side

Which side has the LEAST H+ ions and the MOST OH- ions?

Basic Side

Which side has EQUAL amounts of H+ ions and OH- ions?

Neutral Middle

The strongest acid is the substance w/ a pH closest to __.

0

The strongest base is the substance w/ a pH closest to __.

14

The weakest acid is the substance w/ a pH closest to __.

6

The weakest base is the substance w/ a pH closest to __.

8

What is D an example of?

A Polar Covalent Bond

What is E an example of?

A Hydrogen Bond