Chemistry Review:

(Chapter 3)

Universal Hierarchy

-sequence small to large (or large to small) which interrelates the pieces of the universal puzzle

strings

quarks, leptons, hadrons

sub-atomic particles

protons

neutrons

electrons

atoms

molecules

macromolecules

organelles

cells

tissues

organs

organ systems

organisms

populations

community

ecosystem

Biome

biosphere

planet

solar system

galaxy

galaxy cluster

universe

?????

Vocabulary:

element

compound

atomic number

mass number

isotope

radioisotope

molecule

diatomic molecule

ion

chemical formula

structural formula

mixture

solvent

solute

solution

suspension

colloid

acid

base

neutralization

pH

All matter made up of elements-the smallest part of which, that displays the properties of the element is an atom.

Atoms are the building blocks of matter

There are 90 naturally occurring kinds of atoms (elements), which can be combined in various ways to make compounds.

MOST things are made up of compounds, the functional unit of a compound is a molecule

(the smallest part of the compound that has the properties of the compound)

Element symbols

remember them

Atomic structure

Nucleus

protons (+ charge; mass of 1)

neutrons (no charge; mass of 1)

In much larger space around nucleus-determining the chemistry

electrons (- charge; mass of about 1/2000 or ~0)

Atomic number = number of protons

Atomic mass =

number of protons + number of neutrons

Electron shells:

2 - 8 - 18 - 32

first shell is filled with 2 electrons

second shell with 8

third shell is chemically inert with 8, but can hold 18

fourth shell is chemically inert with 8, but can hold 32

number of electrons always equals the number of protons in an atom

ATOMS ARE ELECTRICALLY NEUTRAL

Isotopes-

same number of protons, different numbers of neutrons

can be, but are not always, radioactive

oxygen 16

8-p 8-n

oxygen 17

8-p 9-n

oxygen 18

8-p 10-n

carbon 12 (most common)

6-p 6-n

carbon 14 (radioactive)

6-p 8-n

H 1 (most common)

1-p 0-n

H 2 (deuterium)

1-p 1-n

H 3 (tritium)

1-p 2-n

Deuterium isn't radioactive

Tritium is

Strontium 88

(most common)

38-p 50-n

Strontium 90

38-p 52-n

radioactive

Radioisotopes used in medicine and as a tracers (Which oxygen comes from water in photosynthesis, the oxygen that is released or the ones in the sugar?)

Uncommon isotopes can be used as tracers, even if they are not radioactive, since the difference can be detected in a mass spectroscope

(commonly called a mass spec)

Bonding:

covalent-sharing electrons-produces molecules

ionic-exchange of electrons-produces ions

Examples:

Covalent-water

Ionic-salt

Sharing electrons creates an attractive force which is called the chemical bond

In a diatomic molecule two atoms of the same element share electrons in covalent bonds to fill their outer energy level (up to 8)

Ionic bonds-

no way to share but exchange---

producing charged particles or ions

opposites attract

(+) sodium

attracts

(-) chlorine

with the force of attraction between two ions called the ionic bond

Sodium Chloride isn't really a molecule. The ions form crystals alternating Na and Cl

Chemical formula:

description of a compound giving ratios of atoms

Structural formula:

how the atoms are arranged

Reactions:

New substances formed

reactants yield products

H₂ + O₂ --> H₂O

But, by conservation of mass, the equation must be balanced-

DO IT

2H₂ + O₂ --> 2H₂O

C₆H₁₂O₆ + O₂ -->

CO₂ + H₂O

Balance it!

C₆H₁₂O₆ +6O₂-->

6CO₂ + 6H₂O

Mixtures:

physically but not chemically combined

Homogenous mixtures

-spread evenly

Heterogenous mixtures

-unevenly spread

Solution-

any homogenous mixture

especially-in a liquid

solvent is the bulk liquid

solute is what is dissolved in the solvent

Don't ask if it is

50% water

50% alcohol

When molecules dissolve the material separates into individual molecules spread throughout the material

When ionic substances dissolve they dissociate, or ionize, with the ions separating

Suspensions:

cloudy, but will settle

Colloids:

particles too small to settle out, but too big dissolve

Smoke is a colloid in air

Milk is a colloid in liquid

Acid-

produces hydrogen ions in solution (H⁺)

Base-

produces hydroxide ions in solution (OH^-)

Neutralization:

acid + base ->

a salt + water

{not necessarily NaCl}

Most of the minerals we use are salts

pH

0 --> 14

7 neutral

0-6.9 acidic

7-14.0 basic

indicators-

change color in different pH solutions

examples:

litmus

red cabbage

phenolthalein

bromthymol blue

methyl orange