Topic: Chemistry

Aim: Explain how elements are classified in the Periodic Table of Elements.

Do Now: http://www.bbc.co.uk/schools/ks3bitesize/science/chemical_material_behaviour/compounds_mixtures/activity.shtml

HW: Other side of homework ditto.

http://www.bbc.co.uk/schools/ks3bitesize/science/chemical_material_behaviour/compounds_mixtures/revise9.shtml

Periodic Table of Elements

• System of grouping all of the known elements and to predict the properties of elements

Element Key

•Atomic number: # of protons –Never changes– Same as # of electrons (in a neutral atom)

–Different for each element

Element Key

•Mass number: protons + neutrons–Round up the atomic mass

How can we determine the # of neutrons?

•Mass # - Atomic #

197-79= 118 neurons

How many protons?

How many electrons?

How many neutrons?

2

24-2 = 2

How are elements

arranged?

•In order of increasing atomic number

Columns • Families or Groups

• Elements have similar BUT NOT identical properties

•Ex: Family 1 (Alkali metals): –are all soft, white, shiny metals–highly reactive

• Ex: Family 2 (Alkaline Earth Metals) –are less reactive than alkali

metals–highly reactive–are shiny

•Ex: Family 13 (Boron Family): –are all soft and metallic

Rows •Periods (7 of them)•Elements are not alike in

properties•Left to right atomic #

increases

4 main categories

of PT

1. Metals: 88 elements to left of zigzag line (metals or metal-like elements)

Topic: ChemistryAim: Explain how elements are classified in the

Periodic Table of Elements.

Do Now:

HW: Color the nonmetals, metalloids and noble gases on your periodic table different colors.

(Chemistry Castle Learning due on Monday!)

Determine the:• # of protons• # of electrons• # of neutrons

2. Nonmetals: to right of zigzag line

Sulfur

3. Metalloids: have properties of both metals and nonmetals

4. Noble Gases (inert gases)

• Group 18 (He, Ne, Ar, Kr, Xe, Rn)

Noble gases glow brightly when an electric charge is passed through them, and so are used as advertising signs: neon tubes glow red, xenon blue, and krypton bluish-white; argon tubes glow pale red at low pressures, blue at high pressures.

Let’s summarize…

1. Explain how the periodic table of elements is arranged.

2. What are the various pieces of information that can be found in an element key?

3. Describe the location of metals, nonmetals, metalloids and noble gases on the periodic table.

Review:

1. Elements in the periodic table are arranged by

2. atomic number

3. atomic weight

4. number of neutrons

5. chemical reactivity

2. Which of these things will you NOT find in the periodic table?

1. Element symbol

2. Atomic weight

3. Atomic orbital radius

4. Atomic number

3. Elements at the left of the periodic table are known as

1. Nonmetals

2. Metals

3. Noble Gases

4. Metalloids

4. Elements at the right of the periodic table are known as

1. Nonmetals

2. Metals

3. Noble Gases

4. Metalloids

5. Which element is a metalloid?

1. S (Sulfur)

2. Si (Silicon)

3. Ba (Barium)

4. Br (Bromine)

5. Volume is

a.the amount of matter in an object

b.the amount of space an object takes up.

c.the gravitational pull on an object.

d.an object's resistance to a change in motion.

 

3. A millimeter is equal to

a. 0.1m

b. 0.01m

c. 0.001m

d. 0.0001m

6. A liter of water contains

a.1000 mL.

b. 100 mL.

c. 10 mL.

d. 1 mL