Notes: Basic ChemistryUnit: The Chemistry of Life

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A. Atom - the basic building block for ALL matter. The smallest unit of an element.

I. Basic Chemistry

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1. Parts of the atom

a. In the nucleus

Protons (+) and

Neutrons (neutral) b. Outside the nucleus

Electrons (-)

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How to Read the Periodic Table

Na11

22.989SodiumATOMIC

Name

ATOMIC Symbol

Atomic Number =

# of protons

OR

# of electrons (if neutral)

Atomic Mass =

# of protons

+ # of neutrons

Practice:

How many protons, neutrons, and electrons does a neutral sodium atom have?

ANSWER

Protons = 11 Electrons = 11 Neutrons = 23 – 11 = 12

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B. Chemical Compounds:

1. Compound - a substance formed by the chemical reaction of 2 or more elements in a definite proportion.

Water H2OSalt NaClGlucose C6H12O6

Hydrochloric Acid

HCl

Ex:

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2. Bonds: formed from attractions between atoms to form compounds

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II. Importance of Water:

A. Most important substance for life.1. Living things are about 2/3 water.

2. Water is required for every chemical reaction.

3. Water is the Universal Solvent.

4. Water is a polar molecule.a. Has positive and negative charge.

Oxygen

Hydrogen

Hydrogen+ +

-

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B. Hydrogen Bonds a weak bond formed between positive and negative ends of water molecules.

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Hydrogen bonds:

1. Surface Tension

water skippers on a pond.

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Hydrogen bonds:

2. Cohesion – water sticks to itself.

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Hydrogen bonds:3. Adhesion – water

sticks to other things.

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C. Mixtures and Solutions

1. Mixture: a combination of substances in which each substance retains its chemical properties.

Ex. Sand and pepper

2. Solution: A combination in which one substance is dissolved into the other.

Ex. Chocolate milk, ocean water

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Solutions

a. Solute: The substance that is being dissolved.

Ex. Lemonade mix

b. Solvent: The substance that the solute is being dissolved into.

Ex. Water

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III. Acids & Bases:

A. Water can break into 2 charged ions:1. Hydrogen ion (H+).2. Hydroxide ion (OH-).

B. Compounds in solution with water cause water to break & become acids and bases.

C. Measure amount of H+ in solution gives the pH.

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1. Acids – forms Hydrogen ions (H+) when mixed with water.

Ex. Hydrochloric acid (HCl)

http://web.jjay.cuny.edu/~acarpi/NSC/images/protexch.gif

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2. Bases – forms Hydroxide ions (OH-) when mixed with water. Also referred to as Alkaline.

Ex. Sodium Hydroxide (NaOH)

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3. pH – number that measures how acidic or basic a solution is.

4. The scale ranges from 0 (most acidic to 14 (most basic or alkaline). The number 7 is neutral.

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At the bottom of your notes, we are going to create a pH scale to use on our next laboratory.

0 147

Neutral

Acidic Basic