Atomic Structure

Bell work 4/5/12

• What are the 3 subatomic particles of an atom?

• What is the electric charge of each one?

What are the 3 major parts of an atom and the charge?

• Proton - Positive

• Neutron – Neutral (no charge)

• Electron - Negative

Atoms

• Smallest piece of matter that still has the properties of the element.

• Atoms are made of:– Protons – have an electric charge of 1+; found

in the nucleus– Neutrons – do not have an electric charge;

found in the nucleus– Electrons – have an electric charge of 1¯;

surround the nucleus in electron clouds

The Periodic Table of Elements

• Atomic number is given at the top of the box for each element.

• The atomic number is how many protons the element has.

• Atomic symbol is the letter(s) in the center of the box.

Mass of Atoms

• Atomic Mass– the total number of protons and neutrons in the nucleus of an atom.

• Nucleus- The dense center of an atom.

• Electron Cloud- empty space around nucleus where electrons are.

How do I know how many protons, neutrons,

and electrons?

• Find the element in the periodic table.• The elements are organized by increasing atomic

number.• Find the mass, and round the number. Ex. 5.6= 6;

5.3=5• Find the atomic number(=number of protons)• Subtract atomic number from atomic mass

(number of neutrons will be the difference)• The number of electrons is the same as the

number of protons.

Bell work 4/6/12

• Draw a diagram showing the location of each part of the atom and the charges.

Draw a diagram showing the location of each part of the atom.

http://www.eskom.co.za/nuclear_energy/fuel/fuel.html

Draw a diagram showing the location of each part of the atom.

See more diagrams at: http://www.bmb.psu.edu/courses/bisci004a/chem/basechem.htm

Draw a diagram showing the location of each part of the atom.

http://www.bmb.psu.edu/courses/bisci004a/chem/atoms.jpg

Draw a Diagram of an Atom

Elements

• Atoms with different numbers of protons are different elements.

• They have different properties (characteristics) based on how many protons they have.

Periodic Table

• The elements are organized by increasing atomic number.

• Vertical columns in the periodic table containing elements with similar properties are called groups.– Every element in a group have the same number of

electrons in the outer energy level.• Horizontal rows of elements that contain increasing

numbers of protons and electrons are called periods.– Elements are classified as metals, nonmetals, or

metalloids.

Groups

• Every element in a group have the same number of electrons in the outer energy level.

• There are seven energy levels, each one has a maximum number of electrons:– 2 electrons– 8 electrons

• Each row finish when the outer energy level is filled

Periods

• Horizontal rows of elements that contain increasing numbers of protons and electrons.

• Elements are classified as metals, nonmetals, or metalloids.

Families• Families -less specific, groups of elements all over the table.

• Examples of Families- Alkali Metals -far left column (Group I) with the exception of H. - Alkaline Earth Metals -the second most reactive family of elements in the periodic table (Group II).- Transition Metals-It all has to do with their shells/ orbitals. They have a lot of electrons and distribute them in different ways. - Halogen Gases-the second column from the right side of the periodic table- Inert Gases (Noble Gases)-located in the far right column of the table

pH Scale

• pH – the concentration of hydrogen ions in a solution

• pH scale - measures how acidic or basic a liquid is

• The scale goes from values very close

0 .- 14. • Acids are found between a number very close to

0 and 7. • Bases are from 7 to 14

pH Scale• Acid: A solution that has an excess of H+ ions. • Base: A solution that has an excess of OH- ions.

Another word for base is alkali.• Aqueous: A solution that is mainly water. • Strong Acid: An acid that has a very low pH (0-4).• Strong Base: A base that has a very high pH (10-14). • Weak Acid: A solution which usually have a pH close

to 7 (3-6).

• Weak Base: A solution that usually have a pH close to 7 (8-10). Neutral: A solution that has a pH of 7. It is neither acidic nor basic.