1. Atoms and their interactions Warm up
What part of the atom has a positive charge and where is it found?

2. the atom What is an atom? What are the parts of an atom?
What is the structure of the atom?
The smallest particle of an element that has the
characteristics of that element
protons (p+); neutrons (n); electrons (e-) n e- P+
Atom: the smallest unit of an element, all matter is composed of atoms. An atom consists of a cloud of tiny particles called electrons tt spin in undefined paths around a small very dense core or nucleus made up of protons and neutrons All living and non living things are made up of atoms.
Proton: positively charged and found in the nucleus
Neutron: are neutral have no charge and are also found in the nucleus
Electron: negatively charged are found moving around the nucleus electrons near the nucleus have less energy than those father away
Nucleus: small, central unit in the atom that contains neutrons and protons
Nucleus contains protons & neutrons, electrons circle the nucleus in an electron cloud

3. something to think about
We all know that “opposites attract” and “like charges repel” –SO:
If electrons are negatively charged and protons are positively charged, why don’t the electrons fall into the nucleus?
Take a minute to answer ?#3 on your worksheet with what you think the answer might be ?

4. something to think about
Niels Bohr proposed a model in which the electrons would stably occupy fixed energy levels around the nucleus, known as orbitals. Each orbital has a limited capacity for electrons.
Because the first energy level is the smallest and the weakest it can hold a maximum of two electrons, the second orbital can hold a max of 8, the third orbital can also hold a max of 8 electrons tho it has more energy than the second orbital because it is farther away from the nucleus. Atoms are stable as long as electrons stay in their orbitals. Modern quantum theories led to stable locations of electrons, which are not exact planetary orbits, but are “clouds” of areas where the electrons may be found.

5. Recipe for an atom
Each element in the Periodic Table has a different number of protons in its nucleus
Protons have positive charge
Change the number of protons  change elements P+
The element also has the same number of electrons
Electrons have negative charge
Change the number of electrons  charge the atom e-
An element is a substance that can not be broken down into a simpler substance. You take a bunch of the same kinds of atoms put them together and you get an element. 90 elements exist naturally on Earth, 25 are essential to living organisms. The periodic table is like a chart of recipe cards to help us build elements. That is how I knew carbon has 6 protons, and sulfur has 16 electrons, I read the recipe card on the periodic table.
Some elements also have neutrons
Neutrons have no charge
They are in the nuclei of atoms n

6. Atomic number Symbol Name Atomic weight Protons = 8 Electrons = 8
Periodic table arranges the element in a specific way and you can learn a lot about the element by the information on the tile as well as where they are placed on the table. Each one of these tiles is like a recipe card for building the atom of that particular element.
You have the symbol – this is what the element is, for this class you will need to become familiar with the symbols for several of the elements including, C, H, O, N, P, S, Fe, and K
Some periodic tables have the name of the element as well
Above the symbol is the atomic number, this tells us the number of protons – oxygen has 6 protons so how many electrons does it have? – 6
The atomic weight tells us how much the atom weighs and since the weight of the atom is determined by the number of protons and neutrons and each weighs 1 atomic mass unit we can take the atomic weight and subtract the atomic number and get the number of neutrons in the atom. You need to round to the nearest whole number. So 16 – 8 = 8 neutrons
Protons = 8
Electrons = 8
16 – 8 = 8 neutrons

7. The electron orbitals # Protons = # Electrons
Stable atoms do not have a charge, if protons are positive, and neutrons are neutral, and the electron is negative how can there be no charge.
In carbon there are 6 protons, 6 neutrons, and 6 electron, the electrons fill up the orbital in order from the one closest to the nucleus on out. 6 electron start with 2 in the first orbital and it is full so we move to the next orbital and the remaining 4 go there. Sulfur has 16 electrons, 2 in the first orbital, 8 in the second, the second is full so the rest go in the third.
# Protons = # Electrons
# Neutrons = Atomic Weight – Atomic #

8. # Neutrons = Atomic Weight – Atomic #
Stable atoms do not have a charge, if protons are positive, and neutrons are neutral, and the electron is negative how can there be no charge.
In carbon there are 6 protons, 6 neutrons, and 6 electron, the electrons fill up the orbital in order from the one closest to the nucleus on out. 6 electron start with 2 in the first orbital and it is full so we move to the next orbital and the remaining 4 go there. Sulfur has 16 electrons, 2 in the first orbital, 8 in the second, the second is full so the rest go in the third.
# Protons = # Electrons
# Neutrons = Atomic Weight – Atomic #

9. Shell structure activityn p
Carbon = C
Sulfur = S
Neon =Ne
Chlorine = Cl
How many protons and electrons do these elements have?
Draw the electron shell structure for each.
3 protons
3 electrons
4 neutrons
Look at your periodic table, which element contains atoms that look like this?
Now do #5 on your work sheet- use colored pencils a different color for each part of the atom

10. Navigating the Periodic Table
The rows are the “periods”
Each period starts a new shell of electrons
The periods are numbered starting with 1 at the top
The columns are the “groups”
Each group has similar chemical properties
The groups are numbered starting with 1 at the left
Elements with similar properties have the same number of electrons in the outermost shell
Something else that you can tell from the periodic table is how many electron orbitals or valance shells the atoms have. All of the element in the first period have atoms with only one electron orbital; all of the electrons in the 5th period have 5 orbitals.
The groups tell us how many electrons there are in the outermost orbital. The elements in the first group have only one electron in the outermost orbital of their atoms; the elements in group 7 have 7 electrons in their outer most orbital. Take a minute and answer questions # 6 & 7.

11. Atoms, Elements and Compounds
Atom: smallest unit of an element
Element: any of more than 100 fundamental substances that consist of atoms of only one kind (C; K; Mg; Ca)
Compound: a collection of 2 or more different atoms, bound together.
H2O or CO2
What is an atom?
What is an element?
A Compound is 2 or more different atoms bound together.
There are 3 different kinds of bonds that can hold the atoms together, and the electrons play a very important part in the bonding of atoms that is why it is important to be able to determine how many electrons an atom has, and how many electrons are in it outer orbital.

12. Cl The mighty electron 17 34 e e e e neon Carbon magnesium chlorine 6P
Let’s check the Borh model you drew for #5 on your worksheet. Carbon, We fill up one orbital before we move to another, 2 in the first, 8 in the second, and 8 in the third. Now we aren’t going to be dealing with any elements that have more than 3 orbitals but be aware there are more than 3 orbitals. Magnesium, Neon - What do you notice about the otter orbital of neon? – It is full. all of the elements in group 8 have full outer orbitals, they have very stable and happy atoms. And Chlorine. Thee is a short hand when writing about elements the upper number is the atomic number which tells us what? The lower number is the atomic mass which tells us what?
neon
Carbon
magnesium
chlorine

13. ionic bond: when electrons are GIVEN & RECIEVED6P
17P
17N e e 6P
17P
17N
11P
11N e
Ionic
bond
Let’s take a closer look at chlorine…. How many electrons are in it’s outer orbital? – 7. only one more electron and we have ourselves a happy atom. If we were to add an electron to the outer shell of chlorine what would happen to it? Answer ?#7 with what you think
If the number of positively charged protons equals the number of negatively charged electrons then we have a neutral atom. If the negatively charged electrons outnumber the positively charged protons we have a charged atom. What charge does it have?
Here we have sodium with it’s 11 electrons, orbitals 1 and 2 are filled up nicely but we have this one lone electron in the 3rd orbital. If sodium lost the only electron in it’s outer shell it would have what kind of charge – more protons than electrons means a positive charge.
Atoms like have complete outer shells, chlorine picking up an electron and sodium getting rid of an electron would make them both very happy even tho it means they would be charged.
The atoms desire to fill up the outer shell is the key to ionic bonding.
Ionic bonding is the giving and receiving of electrons, one atom gives up an electron another accepts an electron. if sodium gave it’s lone outer electron to chlorine then chlorine would have a full outer shell and sodium would have a full outer shell and everybody is happy. The the giving and receiving of an electron holds sodium and chlorine together and this is how we get table salt.
Opposites attract - + Na Cl

14. CHARGE!!! - + Na Cl Ion – an atom with a charge
Cation – an atom with a positive charge
less electrons than protons Na +
Ionic compounds are less abundant in living things that are covalent molecules, but ions are important in biological processes. For example sodium and potassium ions are required for transmission of nerve impulses. Calcium ions are necessary for muscles to contract, and plants absorb essential minerals in the form of ions.
Anion – an atom with a negative charge
More electrons than protons Cl -

15. covalent bond: When electrons are SHARED1P H e 1P H e e 6P
17P
17N 8P 8N O e
Covalent bonds are another way atoms form compounds. Covalent bonding is when two atoms share and electron. Water, for example, two hydrogens and an oxygen are held together by covalent bonds. The hydrogens each have only one electron, their outer orbital is not full, the oxygen has 6 electrons in its outer orbital, how many does it need to have a full outer shell – 2, a match mad in heaven. The hydrogen shares its electron with the oxygen and a covalent bond is formed. e

16. MOLECULES
Molecule – a group of atoms held together by covalent bonds H O 2
Chemical reactions occur when bonds between atoms are formed or broken
A molecule is a group of atoms bonded together. Answer ? #9 Molecules are written in short hand using the symbol for the element. If there are more than one atom of the same element contained in the molecule a subscript is used to denote the number of atoms
Chemical reactions are the breaking and forming of bonds between atoms, the breaking down and forming of molecules that are important for the functioning of organisms. Carbohydrates, proteins, lipids, nucleic acid are all molecules that your body is made of or uses. The bonding together of the atoms that make up these molecules, the breaking of the bonds that hold these molecules together is happening as we speak. There are chemical reaction occurring in you right now.