Atomic Structure 101

Atomic Structure 101

What is matter?

• Matter is everything.  Every single thing that has any mass or takes up any space at all, is matter.

• Even the air is matter, because it takes up space, and contains elements in the form of gas like Nitrogen, Oxygen, and Carbon.

Let's start with matter...

Multiple Select

Why is air considered matter? Select ALL that apply.

• Because it has mass.

• Because it takes up space.

• Because it contains atoms.

• Because you need it to live.

What is an atom?

• All matter is made up of atoms.

• Atoms are the smallest functional unit of matter.

• This means, you can't go any smaller than an atom, and still have chemical or physical characteristics.

• There are as many different atoms, as there are elements on the periodic table.

  Each different type of atom, has different chemical and physical properties.

Multiple Choice

TRUE OR FALSE: The atom is NOT the smallest functional part of matter.

• True

• False

Let's take a closer look...

• This is a carbon atom.

• Carbon has unique physical and chemical properties, because of the structure of the element's atoms.

• A carbon atom contains: 6 protons, 6 neutrons, and 6 electrons.  

• No other atom other than a carbon atom can have 6 protons,

  • the number of protons an atom has is what makes it unique and gives it its properties.

Subatomic Particles

• The SUBATOMIC PARTICLES are the small particles that make up the atom.

• The PROTON is at the center (or NUCLEUS) of the atom, and has a positive (+1) charge.

• The NEUTRON is also at the center (or nucleus) of the atom, and has a neutral (0) charge.

• The ELECTRON circles the NUCLEUS in an orbital similar to planets orbiting the sun.  This is called an ELECTRON CLOUD.  The ELECTRON has a negative (-1) charge.

Multiple Choice

Which particle is in the nucleus of the atom, and has a positive charge?

• Electron

• Neutron

• Proton

• Positron

Multiple Choice

Which particle is in the nucleus of the atom, and has a neutral charge?

• Electron

• Neutron

• Proton

• Positron

Multiple Choice

Which particle orbits the nucleus of the atom, and has a negative charge?

• Electron

• Neutron

• Proton

• Positron

Chemical & Physical Properties

• Each element has CHEMICAL and PHYSICAL PROPERTIES.  This element is Carbon.

• This picture shows pure carbon, and because it is only made up of one type of atom, we can call it an ELEMENT.

• Remember when we talked about how the carbon atom, like all other atoms, are unique?  This is because of its atomic structure, the number of protons, neutrons and electrons it has.

Multiple Choice

If a substance is made up of only one type of atom, it is called...

• a molecule.

• an atom.

• a element.

• a compound.

Carbon Properties

• It's because of the atomic structure of the carbon atoms that we have an element that can burn like coal, can crystallize to create diamonds, and can react with Oxygen to make Carbon Dioxide.  All of those are different types of properties that exist because of the atom's atomic structure.

• Each of those are different types of properties that exist because of the atom's atomic structure.

The Nature of Everything.

• The structure of atoms allows us to understand the true nature of everything in the physical world.

  • It allows us to understand how elements interact with one another.

  • How chemicals combust to move machinery.

  • How leaves change colors.

  • How the atmosphere allows all organisms to survive.

Protons!

• Protons tell us the identity of the atom.

• Protons are at the center of the atom in the nucleus.

• Protons have a positive charge.

• Each atom, or element, has an atomic number.  The ATOMIC NUMBER is the number of protons in the nucleus of the atom.

• Each element is unique from one another because they each have different ATOMIC NUMBERS.

Protons!

• You can find the atomic number for each element by looking at the element's element key in the periodic table.

• The atomic number is usual found at the top.

• For example, just by looking at the element key, I kn​ow that oxygen has 8 protons.

• Only oxygen, has 8 protons.

Multiple Choice

According to the picture of a Helium atom, what is the Atomic Number of Helium?

• 1

• 2

• 3

• 4

Neutrons

• Also in the NUCLEUS of the atom.

• About as large as a PROTON.

• Neutral, or zero charge.​

Multiple Choice

Where is the neutron located in the atom?

• in the electron cloud

• outside the nucleus

• inside the nucleus

• in the neutron cloud

Atomic Mass

• ATOMIC MASS is the mass of the protons plus the mass of the neutrons in the nucleus.

• The atomic mass shows the mass, or size of the atom.

• Different elements have atoms with different masses.

• The electrons are not counted in the atomic mass, because the mass of electrons is much much much smaller.

Atomic Mass

​

• Different elements have atoms with different masses.

Multiple Select

Atomic Mass is the mass of what subatomic particles?

• Proton

• Electron

• Neutrinos

• Neutrons

Electrons!

• Electrons are incredibly small.

• So small that they don't even count towards the mass of the atom.

• They orbit the atom in an ELECTRON CLOUD at incredible speed.

• They are NEGATIVELY CHARGED so they are attracted to the positively charged nucleus.

• They travel way too fast to actually reach the center of the nucleus, so they just orbit around the nucleus instead.

More Electrons!

• Electrons are the part of the atom that is responsible for chemical reactions.  

• ​When you say a substance is "reactive" or not, you are talking about how likely the electrons are to leave the atom's orbit and interact with a different atom.

• Electrons are responsible for bonding.​

• When a chemical reaction occurs, it occurs because electrons have moved from one atom to another creating, or breaking bonds.​

Multiple Choice

When an electron moves from one atom to another, it results in a...

• chemical reaction.

• physical reaction.

Draw

Draw electrons, protons, and neutrons to complete the atom.

​The structure of atoms determines the properties of elements and compounds, and therefore the properties of materials.

​

• Gold shines because of the arrangement of its subatomic particles​.

• Coal burns because of the arrangement of its subatomic particles.​

• Water forms droplets because of the arrangement of its subatomic particles.​