Science 8 Atomic Chemistry Quiz

Are there more atoms in 1 grain of sand, than there are grains of sand on Earth?

Yes, there is more atoms in 1 grain of sand, than grains of sand on Earth.

Elements

• AKA atoms

• The “smallest” unit of matter that ALL KNOWN objects are made up of

How many atoms are found in 12.00 grams of carbon?

602 septillion atoms!

Also known as a mole or Avogadro’s number

What are atoms mostly made up of?

• Mostly empty space ( proved by gold foil experiment)

• Subatomic particles - protons, electrons, neutrons

Protons

• a positive subatomic particle of an atom

• positively charged

• found near in the nucleus ( center )

• mass is 1835/1836 AMU or ~1 AMU

Electrons

• negatively charged subatomic particle in atom

• it is on the outside of the atom, (shell, orbitals, lobes)

• 1/1836 AMU, or ~ 0 AMU

Neutrons

• neutrally, no charged subatomic particle in atom

• in the nucleus (center)

• 1 AMU

AMU

=atomic mass unit

How do we determine the Atomic Mass?

• Add the # of protons to the # of neutrons!

• Ignore the electrons!

• In the periodic table, the atomic mass is an average

• ***ROUND THAT NUMBER ***

ATOMIC NUMBER

=the NUMBER of PROTOMS

How do we determine the number of neutrons?

Atomic Mass - Atomic Number

Number of Electrons

= the ATOMIC NUMBER or # of Protons

Where are Electrons located?

• rings, shells, lobes, orbitals of an atom

Electron Orbitals

• location of electrons

• we need to know the first 3 orbitals K, L, M

• 1st orbital(closest)=K orbital

• 2nd orbital=L orbital

• 3rd orbital=M orbital

• 4th orbital= N orbital

K-Orbital Max

• max of 2 electrons

L-Orbital Max

8 electrons

M-Orbital Max

• 8 electrons(for our class) or 18

Bohr Model

A model of an element that shows the # of electrons in each orbital of an element.

Valence Electrons

Electrons that are located on the last orbital. Does not mean N ORBITAL. Ex. Oxygen has 8 electrons, and so therefore it would have 6 valence electrons.

THE MAXIMUM # OF VALENCE ELECTRONS IS…

8 electrons. An exception of this is helium and hydrogen, they can only have a max of 2 (only have a K orbital)

Lewis Dot Structure

shows only the valence electrons of the element

• want electrons to be close together in pairs

Periodic Table Patterns Families

• Families have the same # of valence electrons, vertical

• Ex. Family 3 has 3 valence electrons

Periodic Table Patterns Periods

• Periods have the same amount of orbitals, horizontal

• Ex. Period 3 has 3 orbitals

As you down a family….

the amount of orbitals increase

As you go across the a period

the valence electrons increase

What’s a nonmetal on the metal side of the periodic table?

Hydrogen only

How many families are there?

8 families

What is 1A family?

Starts with hydrogen, alkali metals, 1 valence electron

What is 2A family?

Alkaline earth metals, starts with beryllium, 2 valence electrons

What is 3A family?

3 valence electrons, starts with boron

What is 4A family?

Starts with carbon, 4 valence electrons

What is 5A family?

5 valence electrons, starts with nitrogen

What is 6A family?

6 valence electrons, starts with oxygen

What is 7A family?

They are halogens, starts with fluorine, 7 valence electrons

What is 8A family?

Noble Gasses, starts with helium, 8 valence electrons

Exception: helium only has a k orbital, 2 valence electrons

It’s a family bc of full valence, and it’s chemical stability

Non-Metals Cut

From boron, staircase to including Uus

Period 1

• only hydrogen and helium

• 1 orbital

Period 2

From lithium, 2 orbitals

Period 3

From sodium, 3 orbitals

Period 4

From potassium, 4 orbitals

Period 5, 6,7

5 orbitals, 6 orbitals, 7 orbitals