This document provides a chemistry review for 9th grade students covering several topics: 1) The three states of matter (solid, liquid, gas) and their particle characteristics. 2) Changes of state including freezing, sublimation, boiling, and melting. 3) Identifying chemical and physical changes and properties. 4) Defining terms like boiling point, melting point, and freezing point. 5) Drawing and interpreting heating curves for elements. 6) Classifying substances as elements, compounds, homogeneous mixtures, or heterogeneous mixtures. 7) Contributions of scientists to the atomic theory model including Bohr's atomic model. 8) Common elements in the human body, Earth's crust,

1. COLEGIO SAN PATRICIO
CHEMISTRY 9th GRADE
REVIEW - 2nd PERIOD
1. States of Matter - Write the 3 states of matter, and the main characteristics of the
particles for each one:
a) ___________________________________________________________________
________________________________________________________________________
b) _____________________________________________________________
__________________________________________________________________
c) _____________________________________________________________
_________________________________________________________________
2. Changes of state - Write the name or description of the Change of State of matter:
a) Freezing: _________________________________________
b) ____________ : process at which a gas becomes a solid
c) Boiling: ___________________________________________
d) _____________: process at which a solid becomes a gas
e) Melting: _____________________________________________
f) ______________: process at which a gas becomes a liquid
3. Identify the following as Chemical or Physical Changes:
a) A tree is cut into boards at a saw mill __________________
b) Food is digested __________________
c) Chocolate is melted for dessert __________________
d) The formation of rust on iron __________________
f) Malt undergoes fermentation to make beer __________________
4. Identify the following as Chemical or Physical Properties:
a) Fluorine has yellow color __________________
b )Alcohol is flammable __________________
c) Mercury is liquid at room temperature __________________
d) Hydrogen reacts with oxygen to form water __________________
e)The boiling point of aluminum is 2519o
C __________________
5. Define Boiling point, Melting point, Freezing point, Condensation point:
a) ______________________________________________________
b) ______________________________________________________
c) ______________________________________________________
6. Draw the heating curve for Phosphorus, if it has a melting point of 44o
C and a boiling
point of 281 C, and then answer the following questions:
a)What is the physical state of Phosphorus at 30o
C? __________________

2. b)What is the physical state of Phosphorus at 50o
C? __________________
c)What is the physical state of Phosphorus at 282o
C? _________________
d)What is the physical state of Phosphorus at 44o
C? __________________
Heating curve:
7. If the statement is true, write “TRUE” on the line, and if it is false, change the underlined
word or words to make it true:
a)Matter has three forms: element, compound and mixture. _________________
b)Matter has three states: solid, liquid, and gas. ____________________
c)Mixtures cannot be separated by physical methods ____________________
d)Mixtures can be homogeneous or heterogeneous ____________________
e)Elements are made of a single atom ____________________
f)Pure substances can be elements or compounds ____________________
g)The proton and electron are opposite in charge ____________________
h)The proton and neutron have approximately the same mass _________________
i)The electron and proton are inside the nucleus ____________________
j)The neutrons are outside the nucleus ____________________
k)The proton has positive charge ____________________
l)The neutron has positive charge ____________________
m)The electron has no charge ____________________
8. Classify the following substances as: element, compound, homogeneous mixture or
heterogeneous mixture:
a) helium (He) _______________
b) Carbon dioxide (CO2) _______________
c) Tin (Sn) _______________
d) Tungsten (W) _______________
e) water _______________
f) silver (Ag) _______________
g) salt (NaCl) _______________
h) air _______________
i) blood _______________

3. j) orange juice _______________
k) sulfuric acid (H2SO4) _______________
l) chocolate chip cookie _______________
m) muddy water _______________
n) gasoline _______________
9. Name the scientists who contributed the most for the development of the atomic theory
and the model they proposed (in order, from the latest to the most recent)
a)
b)
c)
d)
e)
10. Draw the Bohr’s atomic model, and label the 3 subatomic particles:
11. The most common elements in the human body are: _________________________
12. The most common elements in the Earth’s crust are: _________________________
13. The most common element in the Universe is: ___________________
14. Write an example of mixture that can be separated using each of the following methods,
and a drawing for each:
a)Chromatography

4. b)Decanting
c)Distillation
d)Evaporation
e)Filtration
15. A glass of milk has a volume of 100ml. If the milk has a mass of 103g, what is the density
of milk?
DATA FORMULA OPERATION ANSWER
16. If four liquids are placed in a test tube, draw the order in which they will set:
A=7.7 g/ml C= 0.6 g/ml
B= 1.2 g/cm3
D= 4.3 g/cm3
17. Also study from the QUIZZES, WORKSHEETS and PRACTICE from the notebook.