Applied Science

Chemistry Unit(atoms, elements, molecules,

compounds, pH, water)

Name: ________________________________

1

I. ___________________________ is anything that has mass and volume.

A. Examples of Matter Examples on things that are not Matter

_____________________ _____________________

_____________________ _____________________

_____________________ _____________________

B. All matter is made up of very ______________, basic particles called _____________. So Atoms are the building blocks of everything in the universe.

II. ATOM: The basic ____________________ of an _____________________ (building blocks of everything).

A. Atoms are made up of ________________ particles: Protons, Neutrons, and Electrons.

B. The center of an atom is called the ___________________________.

C. ________________________

1. Found in the _____________________

2. Have a __________________________ electrical charge

3. Are ________________________ compared to ______________________

D. ________________________

1. Found in the _____________________

2. Have __________ electrical charge (they are ____________________)

3. Are ____________________ compared to Electrons

2

E. _________________________

1. Found _______________the nucleus in orbits (__________________) also called the electron cloud.

2. Have a _________________________ electrical charge.

3. Are ________________________ compared to Protons and Neutrons.

F. Use the information above to fill in model of an atom.

G. Complete the table using your notes:

Particle Where is it? What’s its charge? Heavy or Light?PROTON

ELECTRON

NEUTRON

H. Atoms generally have the same number of ______________________ and

_____________________ so the overall charge of an atom is ____________________.

3

III. Element : A pure substance made up of only one __________________________.

A. Elements _______________ be __________________ down into simpler substances.

1. Carbon is an ________________, it is made up of ______________ atoms.

2. Oxygen is an ________________, it is made up of ________________ atoms.

B. There are more than 115 __________________________________ so there are more

than 115 kinds of ____________________.

C. Elements are arranged on the ______________________________________.

The periodic table

D. Each block on the periodic table holds information about ______________________.

4

E. The element information is in ________________________________ depending on the periodic table you are looking at.

1. What is Lithium’s Atomic Number? _________

2. What is Lithium’s Atomic Mass? _________

3. What is the symbol for Lithium? __________

F. The periodic table has information about the element such as it’s ________________ of protons, number of electrons, and number of neutrons.

G. FORMULAS

1. Atomic Number = # of Protons = # of Electrons ___________________

2. Atomic Mass = # of Protons + # of Neutrons ___________________

3. # of Protons = Atomic Mass - # of Neutrons ___________________

4. # of Neutrons = Atomic Mass - # of Protons ___________________

H. Remember: Electrons are very ___________________ so they don’t count towards

the ________________________________ of the element.

I. When using the Atomic Mass – _______________- the ________________ to the nearest whole number if necessary.

Practice

1. What element? _______________________

2. What is the atomic number? _________

5

3. What is its chemical symbol? ________

4. What is the atomic mass? _________

5. How many protons does it have? _________

6. How many electrons does it have? _________

7. How many neutrons does it have? ________

J. The periodic table is arranged based on the number of ____________________ in each element (its atomic #).

1. Element ____ is Hydrogen which has _________________2. Element 2 is Helium which has 2 protons3. Element ____ is Lithium which has ____ protons

Reminder: Elements have ____________________ (are neutral) so the number of

_________________ is _______________ to the number of _________________.

IV. ___________________ MODEL – a drawing showing where ____________________ are located around an atom.

A. __________________ and __________________ are found in the nucleus. These can be drawn in with circles or just written in with the number and type of particle.

B. Examples of a nucleus with _____ protons and _____ neutrons

6

C. Electrons are found on ______________________ (also called energy levels or shells) around the nucleus.

1. The ______________ orbital (innermost) holds up to _____________________.

2. The 2nd and 3rd orbital hold up to _______________________________.

D. VALENCE ELECTRONS are the electrons on the _______________________________.

1. Valence electrons are important because they determine what an atom will

_________________________ (connect) with.

7

E. Steps to create a Bohr model of an atom/element:

1. Determine ______________ of protons, neutrons, and electrons to be drawn.

2. Draw a circle for the __________________ and add the proper _______ of protons and neutrons.

3. Start adding electrons to the __________________ with a maximum of ______ on the first orbital and _______ on the others. Do not add a new orbital until the inner one(s) have the maximum number of electrons on it.

Example

Bohr model of Lithium with 3 protons, 3 electrons, 4 neutrons

3 protons and 4 neutrons drawn in nucleus

2 electrons fill first orbital but one more still needed so a second orbital is added where the last electron is placed.

F. You can tell which _______________________ a Bohr Model shows by counting the number or electrons OR looking at the number of protons (remember # P= # E and this is the atomic number which you can look up on a periodic table).

What Element? _____________________ What Element? _____________________

8

V. Molecule: _________ or ___________________________ joined together to make bigger particles.

A. Molecules __________ be made up of the _________________________ of atom

(element) or _________________________________ of atoms (elements).

B. Molecules can be thought of as a way to measure _____________________________ of something

C. Examples

1 molecule of oxygen gas _______

2 molecules of Oxygen gas _______

4 molecules of Carbon Dioxide _______

VI. Compound : A pure substance that is made up of __________ or

_____________ types of ___________________________ (atoms).

A. Note: All compounds are molecules but ____________ all molecules are compounds.

Identify the following as molecule only or both compound/molecule

O2 ______________________________________ C6H12O6 ______________________________________

4 CO2 ______________________________________ 2N2 ______________________________________

VII. CHEMICAL FORMULAS

A. Just as each element has its own chemical symbol, each compound or molecule has

its own _________________________________.

9

B. A chemical formula gives _______________ pieces of information:

1. What _________________ are in the ___________________ (given by the symbol of the element).

2. How many _______________ of each ____________________ are in the compound.

C. The number _________________ the symbol (and is partially below the symbol) is

called the ________________________. This is the number that tells how many

__________________ of that element in the compound.

Example: C6H12O6 ______, ______, and ______ are the subscripts

______atoms of carbon, ______ atoms of hydrogen, and ______ atoms of oxygen

D. ____________subscript means there is only ________ atom of that element in the molecule.

Example: H2O

___ atoms of ________________ and ___ atom of _________________

E. A number _____________________ the chemical formula of a molecule is called the

__________________________, and tells ____________________ of that molecule there are.

Example: 5H2O The coefficient is ______

_______________________________of water (H2O)Those _____ molecules of water contain ______ atoms of hydrogen and ______ atoms of oxygen.

10

F. Another way to look at coefficients and subscripts

___________ = H + H + O

___________ = H + H + OH + H + O

___________ = H + H + OH + H + OH + H + O

G. To determine the number of atoms in a compound with a coefficient you

_________________ the ___________________ by each ___________________.

Example

3 CO2 The coefficient is ______, The subscript for Carbon is ____ and the subscript for Oxygen is ____

Coefficient x subscriptsCarbon: 3 X 1 = 3 total carbon atomsOxygen: 3 X 2 = 6 total oxygen atomsTotal Atoms in the compound = 9

2 NO3 # of Nitrogen Atoms: _______# of Oxygen Atoms: _______Total # of Atoms: ______

H. Sometimes there are __________________________ around part of the compound’s chemical formula.

K(OH)2 The subscript shows that OH is there twice

________________________________

11

I. To find the __________________ of __________ here you _____________________ the coefficient by the subscript by the subscript of the brackets (last part only for elements in the brackets)

K(OH)2 Coefficient x subscript x subscript of brackets

Potassium (K): 1 X 1 = 1 total potassium atomOxygen: 1 X 1 X 2 = 2 total oxygen atomsHydrogen: 1 X 1 X 2 = 2 total hydrogen atoms

Practice

H2(SO3)2 2F(OH)2

H: __________________________ F: __________________________S: __________________________ O: __________________________O: __________________________ H: __________________________

________________________________________________________________________

VIII. pH - A measure of how _________________ or _________________ a solution is.

A. The pH scale goes from ______________________.

B. Substances with a pH between _____ and _____ are acidic (_______________).

C. Substances with a pH between _____ and _____ are basic (________________).

D. Substances with a pH of 7 are _____________________. They are not acidic or basic.

12

E. The ______________________ away from neutral, the ______________________ the acid or base.

________________________________________________________________________

IX. Water

A. Water is made of 2 atoms of _________________ and 1 atom of _________________

B. They are held together by ___________________ bonds, so the electrons are shared.

C. DRAWING OF A WATER MOLECULE

X. POLARITY

A. The oxygen atom ______________________________ on the ___________________

than the hydrogen atoms do. So the electrons stay ______________ to the oxygen atom

giving it a relatively ___________________________(-) charge.13

B. This means that the only thing left of the hydrogen

atoms is their ______________________ that

have a ______________________ (+) charge.

C. A water molecule is _______________________ because it has a (____) side and a

(_____) side, but overall, it is ____________________________.

D. These sides with opposite charges are attracted to each

other and form _____________________ bonds

XI. Properties of Water

Polarity causes water to have many interesting qualities:

A. ____________________________ - water molecules stick to each other

1. Water will stack up on a _____________________

2. Bodies of water have ___________________________on top that some insects can walk on.

14

B. ____________________________ - water molecules stick to other polar molecules (other things)

1. Water is ________________________ by paper towels, sponges, and the roots of plants

C. Water is a good ____________________________ - it dissolves substances easily.

1. It does not dissolve non-polar molecules like _____________.

2. This is how _____________________ such as oxygen and energy from food travel through our bodies (dissolved in water in our blood).

NOTE: Cohesion, Adhesion, and being a Solvent are due to water being a

________________________ molecule.

E. When water freezes, it gets __________________ dense

1. This causes ice to __________________, and insulate bodies of water in the winter.

15