PART THREE CHEMISTRY NOTES

Introduction:

1. Alchemists – people who started the concept of chemistry and studying chemistry in labs.

2. Elements –

a. Matter – solid, liquid, gases

b. Elements – what matter is composed of

c. Natural elements – elements found in nature

d. Compound – two or more elements

e. Atoms – smallest particles of elements

3. Atoms –

a. nucleus – center of atom

i. 99.9 % of atom’s mass

ii. positive electric charges located there

iii. determines type of element

iv. consists of two types of particles

1. protons – positive charges

2. neutrons – no charge

b. protons – positive charges

i. number of protons in nucleus determines type of element

ii. atomic number represents protons in atom

c. atomic mass number - sum of protons and neutrons in the atom

d. quarks – protons and neutrons made up of smaller particles

e. electrons – negative charge

i. move spherically around the nucleus, NOT a flat orbit

ii. held in an atom by electric forces

f. nuclear force – hold neutrons and protons together

f.

g. quarks – protons and neutrons made up of smaller particles

h. electrons – negative charge

i. move spherically around the nucleus, NOT a flat orbit

ii. held in an atom by electric forces

i. nuclear force – hold neutrons and protons together

j. shell – specific energy level around nucleus

i. fill the shell with electrons closest to nucleus first.

ii. Proceed filling each outer shell in succession according to that element.

Sodium atom

4. Periodic Table of Elements –

a. Mendeleev – grouped elements

b. Elements arranged in order of increasing atomic # in horizontal rows

c. Period – horizontal rows

5. Families – vertical rows

i. Similar properties

ii. Metals on the left

iii. Non-metals on the right

iv. Transition metals don’t fit into any family

MAIN GROUP FAMILIES IN THE PERIODIC TABLE

Alkali Metals

Alkaline Earths

Boron Family

Carbon Family

Nitrogen Family

Chalcogens

Halogens

Noble Gases

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

2 He

3 Li

4 Be

5 B

6 C

7 N

8 O

9 F

10 Ne

11 Na

12 Mg

13 Al

14 Si

15 P

16 S

17 Cl

18 Ar

19 K

20 Ca

31 Ga

32 Ge

33 As

34 Se

35 Br

36 Kr

37 Rb

38 Sr

49 In

50 Sn

51 Sb

52 Te

53 I

54 Xe

55 Cs

56 Ba

81 Tl

82 Pb

83 Bi

84 Po

85 At

86 Rn

87 Fr

88 Ra

5. Compounds –

a. Substance made of two or more elements

b. Usually same elements in same proportions

6. Mixture –

a. Two or more elements OR compounds not chemically combined

i. Example: sea water; orange juice; mayonnaise; cereal and milk

b. proportions vary

c. solutions – uniform ally mixed (sugar water)

7. Molecules –

a. Two or more atoms

b. Chemical bond – atoms fitting together to make a molecule

c. Diatomic molecule – only two atoms join together

8. Ionic Bond –

a. Atom shifts an electron to another atom

i. Example table salt

ii. extra proton – positively charged (positive ion)

iii. extra electron – negatively charged (negative ion)

9. Crystals – atoms are arranged in a regular pattern in a solid.

a. Strong attraction of ionic bonds

10.

http://lc.brooklyn.cuny.edu/LeftBarFiles/FromAboutLC/Core71Files/Bonds.html