Unit 3: Atoms and Elements – Review Notes

Unit 3: Atoms and Elements – Review Notes

name:_______________________

period: ______________

Main Idea

Supporting Details/Answer

1. 
   What is an atom?
   

The smallest particle into which an element can be divided and still be the same substance.

2. 
   What is an element?
   

Pure substance that can’t be separated into simpler substances by physical or chemical changes.

3. 
   Draw and identify the basic parts of a periodic table.
   

7

N

Nitrogen

14 amu

Atomic #

Symbol

Name

Atomic Mass

4. 
   Where are protons, neutrons and electrons located in an atom?
   

Protons = nucleus

Neutrons =nucleus

Electrons = electron cloud

5. 
   What is an atom mostly made up of?
   

empty space

6. 
   What are the charges on a proton, neutron and electron?
   

Protons = positive

Neutrons =no charge; neutral

Electrons = negative

7. 
   Where is most of the mass of an atom located?
   

Nucleus because protons and neutrons are in the nucleus and they both have mass

Electrons are in the electron cloud and have almost no mass

8. 
   What units are used to measure the mass of an atom?
   

amu= atomic mass unit

9. 
   Describe how to determine the number of protons in a specific atom using the periodic table.
   

The atomic number = number of protons

10. 
    Describe how to determine the number of electrons in a specific atom using the periodic table.
    

Electrons = protons in neutral atoms

11. 
    Describe how to determine the number of neutrons in a specific atom using the periodic table.
    

Neutrons = atomic mass - protons

12. 
    What are some of the patterns on the periodic table?
    

Down a group: atomic radius increases, number of energy level increases, reactivity is same, number of valence electrons is same

Across a period: number of valence electrons increases, number of energy levels is same

Group # = number of valence electrons

Period # = number of energy levels

Metals are on the left

Nonmetals are on the right

Metalloids are along the zig zag line that separates metals and nonmetals

13. 
    What determines the type of element?
    

The atomic number = number of protons.

The number of protons an atom has = the type of element. No two different elements have the same number of protons.

14. 
    What is all matter made of?
    

Atoms.

15. 
    What are the periods and groups on the periodic table?
    

Properties of matter are ways of describing matter.

16. 
    Define chemical property of matter:
    

A chemical property of matter can only be observed by reacting matter with other matter to create a new type of matter. Chemical properties describe the ability of a type of matter to react with other matter.

17. 
    Define physical property of matter:
    

A physical property can be observed without changing the matter into a new substance.

18. 
    Practice drawing Bohr models. Tell how many electrons the first three energy levels can hold.
    

1^st energy level holds 2 electrons

2^nd energy level holds 8 electrons

3^rd energy level holds up to 18 but is considered full with 8 electrons


6

C

Carbon

12.0



Atomic number
1. Identify


Element symbol



Element name


Atomic mass

Word	Definition
Atomic Number	The number of protons in an atom. In a neutral atom it is also the number of electrons.
Chemical Symbol	The symbol that represents that element
Element Name	The name of the element
Mass Number	The mass of an atom of that element. It is the total number of protons and neutrons.

10

10

3

3



neon

10

20.18

10

4

3

6.941

lithium