Introduction to the

Periodic TableInit: 9/18/2008 by Daniel R. Barnes

. . . explain the meaning and origin of information found on the periodic table.

“SWBAT = “Students will be able to”

Atomic number = number of protons

The atomic number defines the element.

If an atom has 11 protons, it’s a sodium atom, guaranteed.If an atom is a sodium atom, it has 11 protons, guaranteed.

If it hasn’t got 11 protons, it’s not sodium. It’s some other element

First letter upper case, all others lower case

The symbol and the name don’t always match.

When this happens, it’s probably because the symbol is taken from the Latin name for the element.

=

Natrium

The Roman Empire

“Ferrum” is Latin for “iron”.

“Argentum” is Latin for “silver”.

“Aurum” is Latin for “gold”.

Multi ex scientia verba

latina (?)*

“Stannum” is Latin for “tin”.

26

Fe55.85

47

Ag107.87

79

Au196.97

50

Sn118.71

* I used the translate function on iGoogle for this. I don’t think it’s trustworthy for English Latin, to tell you the truth.

You get to use the CST Refence Sheet on all the tests in this class.

Therefore, you don’t have to memorize all the names and symbols of every element on the periodic table.

It helps, though.

Although it would surprise Dalton to find this out, not all the atoms of an element have the same mass.

An atom of an element is guaranteed to have a certain number of protons (the atomic number of the element).However, an atom does not have to have a specific number of neutrons to be in that element.

Therefore, each element occurs as several different isotopes, each of which has a specific mass number.Most carbon atoms are carbon-12 atoms, but there are some carbon-13 atoms, also. That drives the average mass up a bit.

6

Ccarbon

12.01

Q1: What is the atomic number of silicon and what does this mean?A: The atomic number of silicon is 14, which means all silicon atoms have 14 protons, and any atom with 14 protons is a silicon atom.

Q2: What is the difference between Co and CO?A: “Co” is the symbol for cobalt, a metallic element. “CO” is the formula for the compound carbon monoxide, a colorless, odorless, and highly toxic gas.

Q3: Why is the symbol for silver “Ag” instead of “S” or “Si”?A: “S” was already taken by sulfur, and “Si” was already taken by silicon. Therefore, scientists based the symbol for silver on silver’s Latin name, “argentum”.

. . . describe the location of any element on the periodic table.

“SWBAT = “Students will be able to”

Period one

Period five

Period seven

Period seven

Co

lum

n o

ne

Co

lum

n s

ix

Co

lum

n e

igh

teen

Gro

up

on

e

Gro

up

six

Gro

up

eig

hte

en

What element is at Row 4, Column 12?

What element is at Period 6, Column 3?

What element is at Row 2, Group 17?

What is the location of manganese?

Period 4, Group 7

What is the location of platinum?

Period 6, Group 10

What is the location of argon?

Period 3, Group 18

. . . relate the position of an element on the periodic table to its atomic number and atomic mass.

“SWBAT = “Students will be able to”

Look at what the average atomic masses do as atomic number increases

http://web.mit.edu/course/3/3.091/www3/pt/pert3.html

Ave

rage

Ato

mic

Mas

s/am

u

Atomic Number

Average Atomic Mass vs. Atomic Number

18

Ar39.95

19

K39.10

27

Co58.93

28

Ni58.69

52

Te127.60

53

I126.90

There are more reversals around here, somewhere,

but don’t worry about them right

now.

I’ve darkened each square here in proportion to the atomic number of the element in the squareThe darker it is, the heavier it is.Where are all the light elements?

Where are all the heavy elements?

What happens to average atomic mass as you go to the right?

What happens to average atomic mass as you go down a column?

It gets larger.

It gets larger.

Q4: What is the relationship between position on the periodic table and atomic mass/atomic number?A: Atomic numbers and atomic masses get larger as you go down or to the right.

User name = hwbrainpop

Ask Mr. Barnes for password. Can’t give it here. I post this ppt on the www. (9/16/2014)

View the “Periodic Table of the Elements” cartoon once you’ve logged in.

The student account is only good from the hours of 8AM – 4PM.

TheEnd

18

Ar39.95

19

K39.10

27

Co58.93

28

Ni58.69

52

Te127.60

53

I126.90

Scrap Junkyard

Not part of lecture!