The Three Primary Subatomic Particles...
Protons (positive) Neutrons (neutral) Electrons (negative)
Note: protons and neutrons are made up of even smaller particles called Quarks
# of protons = the atomic number Atomic number = # of protons # of protons determines which
element it is! Who is element # 15? How many protons does lithium have? What is the atomic number of tin?
50
Phosphorus3
Number of neutrons can vary, even for the same element.
Neutrons affect the atomic mass Isotopes
same # of protons (same element) different # of neutrons (isotope)
Elements can have many different isotopes Carbon-12, Carbon-13, Carbon-14, Uranium-235, Uranium-238
Neutrons contribute to the “Strong Force” that holds the nucleus together.
Sum of the protons and neutrons
Electrons are not included Too small (1/2000)
What is the atomic mass of this atom?
A neutral atom has no charge.
positive charges = negative charges.
A neutral atom has the same # of electrons as protons
How many electrons does this atom have?
Atomic Number
Protons + Neutrons
Atomic Mass
#Protons
Element Symbol
# Neutrons = Atomic Mass – Atomic Number
Cl3517
17 protons17 electrons35-17 = 18 neutrons
95 protons95 electrons243-95 = 148 neutrons
Am24395
If an atom is not neutral, then it has a charge.
Ion Charged particle
This atom has: 3 protons (++
+) 2 electrons (- -) Net charge is +1 and
it is written as Li+1
It is called a Cation
If an atom is not neutral, then it has a charge.
Ion Charged particle
This atom has: 9 protons (++++++++
+) 10 electrons (- - - - - - - - -
-) It is written as F-1
It is called an Anion
How many protons?– The atomic number
How many neutrons?– Atomic mass minus atomic number
How many electrons (if the atom is neutral?)– Same as # of protons
Ion: Anion: Cation: Isotope:
Atomic number: Atomic mass:
Charged Particle
Same # of Protons, Different # of Neutrons.
# of ProtonsProtons + Neutrons
Negatively Charged Particle
Positively Charged Particle
Just like members of a family, certain elements of the periodic table share similarities. Like good looks!
Families of elements are groups of elements that have similar properties.
Groups can be a single column or a whole section of the periodic table.
Let’s start with the big groups first.
Similar metals are grouped together.
Two groups of metals are located on the left side of your periodic table.
Some are located on the right side of the table left of the stair steps. Most are located in the middle of the periodic table.
The elements that are intermediate conductors of heat and electricity. (can do it but only under certain conditions)
Sometimes called Metalloids Found by the “stair-step” divider
between metals and non-metals
Specific groups that have similar properties are in the columns on the periodic table.
These are the numbers 1-18 or 1A -8A across the top of the table.
The highly reactive metallic elements located in Group 1 of the periodic table.
Tend to lose 1 electron
They are Cations (+1 charge)
React with water
sodium and potassium Brainiac
The reactive metallic elements located in Group 2 of the periodic table.
Tend to lose 2 electrons
They are Cations (+2 charge) Do not react with
water.
Lumps of Calcium
The alkaline-earth metals make up the second column of elements from the left edge of the periodic table.
These are metallic elements in Group 3-12 of your periodic table.
They are “transition metals” because they shift from being similar to group 2 (alkali metals) over to being like group 13 moving left to right.
The highly reactive elements located in Group 17 of the Periodic table.
Are all diatomic(F2, Cl2, Br2, I2) Atoms Tend to gain 1 electron They are Anions (-1 charge)
HalogenLamps
Bromineburning
Noble gases are located on right edge of the periodic table.
And on the throne when kings and queens fart !
Diatomic = two atoms There are 7 diatomic atoms N2, O2, F2, Cl2, Br2, I2, H2
Remember them by the rule of “7” Starts with element 7 = Nitrogen Forms a 7 through oxygen and down to iodine The 7th diatomic element is hydrogen