Unit 1 Chemistry

Review of Basic Chemistry

name charge symbol mass location

proton

electron

neutron

+

-

o

p+

e-

no

1 amu

1 amu

1/1837 amu

nucleus

nucleus

orbiting the nucleus

1 amu = 1.67 x 10 -24 g

A: Subatomic ParticlesAtoms are composed of protons, electrons, and neutrons.

Electrons carry a negative charge and move around the nucleus.

The nucleus is made up of positively charged protons, and neutrons, which have no electrical charge.

Size of 1 Atom:An atom is around 0.1 nanometer, or 100 picometers.

http://www.powersof10.com/film

B: Structure of Atoms

• In a neutral atom, the number of protons (atomic number)= the number of electrons.

• The mass number = # protons + # neutrons.

• Each electron orbital can hold a certain number of electrons:

1st orbital can hold only 2 e- (inner most)

2nd orbital can hold only 8 e-

3rd orbital can hold only 8 e-

4th orbital can hold only 18 e-

Atomic structure of a fluorine atom:

Electrons do NOT orbit the nucleus like planets orbit the sun

Rather, they occupy “areas of probability” around the nucleus

Element Number of Neutrons

Number of Electrons

Number of Protons

Mass Number

    11   23

  6     12

        19

      16  

uranium        

  61   47  

1112sodium

66carbon

fluorine 9910

16sulphur 32169292 238146

47 108silver

How many electrons does a sodium atom have in its outer orbit?

How many electrons does carbon have in its outer orbit?

How many neutrons does a nickel atom have?

How many electrons does hydrogen have?

How many electrons does helium have in its outer orbit?

Does oxygen have a complete outer electron orbit?

one

four

31

one

two

No – 6 electrons

The Periodic Table

Constructing a “Periodic Table”

look at each animal and make brief notes about its appearance

when we have seen all of the animals, you will arrange them into logical groups based on ?

tiger

1 m

eland

1 mzebra

1 m

wild horse

1 m

coyote

1 m

impala

1 m

jackal1 m

wildcat

0.3 m

lynx

1 m1 m

kudu

wild ass

1 m

1 m

timberwolf

1 m

gazelle

leopard

1 m

now put these animals into two logical groups

now divide the two groups each into two subgroups

then organize them in the same pattern within each group

wildcat lynx

leopard

tiger

wild ass

zebrawild horse

gazelle

impala

kudu

eland

jackal

coyote

wolf

we can arrange them into groups by appearance and then within groups, by size

wildcat lynx

leopard

tiger

wild ass

zebrawild horse

gazelle

impala

kudu

eland

jackal

coyotetimberwolf

wildcat lynx

leopard

tiger

jackal

coyotetimberwolf

wild ass

zebrawild horse

gazelle

impala

kudu

eland

carnivoresherbivores

take lifegive up life

Not all herbivores are equal, some give up life more easily

Not all carnivores are equal, some take life more easily

now let’s relate this to the real

Periodic Table of Elements

C: The Periodic Table

• The periodic table is made of three types of elements;

1. metals (give up electrons)

2. non-metals (take electrons)

3. metalloids (bit of both)

boron, silicon, germanium, arsenic, antimony, tellurium, polonium

A chemical group/family is a vertical column of elements that have similar physical and chemical properties.

Column 1: alkali metals

Column 2:  alkaline earth metals

Column 3-11: transition metals

 Column 17: halogens

 Column 18: noble gases/inert gases

 Two Rows at Bottom: rare earth metals

On the periodic table there are 18 vertical groups.

based only on atomic properties the Periodic Table would look like this!!

for convenience, we pull out the rare earths so the Periodic Table looks like what we see

Periods

•Periods are horizontal rows of elements.

•The first period (row) contains 2 elements. 

•The second period (row) contains 8 elements etc.

•The properties of an element gradually change across a period. 

•The size of an atom gets smaller as you move across a period.

Valence electrons:• Electrons that occupy the outermost orbital are

responsible for the chemical behavior of the element.

sodium atom

D: Lewis Diagrams• Lewis diagrams show the number of electrons in the

outermost orbit only.

R1

2

3

45

67

8

Take out a piece of paper and make Lewis diagrams for

B, Be, C, Cl, F, H, He, Li, Mg, N, Na, O, P, S

http://www.google.ca/url?sa=i&rct=j&q=lewis+diagram&source=images&cd=&cad=rja&docid=xEyrmmtYg6eGKM&tbnid=tHjI66HXGvLGtM:&ved=0CAUQjRw&url=http://jahschem.wikispaces.com/valence+theory&ei=6cIZUfn8DaPr2QWfz4HQAg&bvm=bv.42261806,d.b2I&psig=AFQjCNHtm_S2sF86FE63fYoD-oA67uw8pw&ust=1360729163846153