Revision sheet for Final Exam Grade (9) Chemistry Term2 ... · 5) Write the definition of Law of definite proportions ? P.70 A compound contains the same elements in exactly the same

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By: Mrs. Raghad, Chemistry teacher

Name: ………….……………… Grade 9 ( )

Revision sheet for Final Exam

Grade (9)

Chemistry

Term2

2019-2020

Materials for the Exam, you should Study from:

Chapter(3)

Lesson(1) The Atom Theory

Lesson(2) The structure of the Atom

Lesson(3) Counting Atoms

Interactive Book: Pages ( 69 – 83 )

The Revision sheet

NGSS: HS-PS1.A.1

HS-PS1.A.2

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A) Answer these questions: ATOMS: THE BUILDING BLOCKS OF MATTER

1) Write the definition that illustrates the law of conservation of mass.

_____________________________________________________________________

_____________________________________________________________________

2) State two principles from Dalton’s atomic theory that have been revised as

new information has become available.

1)____________________________________________________________________

2)____________________________________________________________________

3) The formation of water according to the equation 2H2 + O2 2H2O

Shows that 2 molecules (made of 4 atoms) of hydrogen and 1 molecule (made of 2

atoms) of oxygen produce 2 molecules of water. The total mass of the product, water,

is equal to the sum of the masses of each of the reactants, hydrogen and oxygen.

1-What parts of Dalton’s atomic theory are illustrated by this reaction?

2-What law does this reaction illustrate?

1)____________________________________________________________________

2)____________________________________________________________________

4) List the 3 Laws of Atomic Theory? P.70

1)____________________________________________________________________

2)____________________________________________________________________

3)____________________________________________________________________

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5) Write the definition of Law of definite proportions ? P.70

_____________________________________________________________________

_____________________________________________________________________

6) PROBLEMS:

Write the answer: Show all your work in the space provided:

1) If 3 g of element C combine with 8 g of element D to form compound CD.

How many grams of D are needed to form compound CD2?

__________________________________________________________________

__________________________________________________________________

2) Complete the following equations:

C + O ………..….

CO ……….. + …….….

C + O + O ……………...

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3) A sample of baking soda, NaHCO3, always contains 27.37 % by mass of

Sodium, 1.20 % of hydrogen, 14.30 % of carbon, and 57.14 % of oxygen.

a. Which law do these data illustrate?

_______________________________________________________________

b. State the law.

_______________________________________________________________

_______________________________________________________________

7) CHOOSE THE RIGHT ANSWERS:

1. The protons and neutrons are located in the ……… of the atom.

a. center b. orbits

c. outside d. none of the above

2. The negative charged disk in the electrical analysis is called……:

a. cathode b. water

c. solution d. anode

3. Atoms contains ……………… particles:

a. positive b. negative.

c. positive and negative d. neutral

8) Nitrogen and oxygen combine to form several compounds, as shown by the

following:

Compounds Mass of nitrogen that combines with 1 g oxygen

NO 1.70 g

NO2 0.85 g

NO4 0.44 g

Which law do these data illustrate?

__________________________________________________________________

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B) SHORT ANSWER: THE STRUCTURE OF THE ATOM: p.74-79

Answer the following questions in the space provided.

1) In cathode-ray tubes, the cathode ray is emitted from the negative electrode,

which is called the _______________

2) The smallest unit of an element that can exist either alone or in molecules

containing the same or different elements is the__________________.

3 ) A positively charged particle found in the nucleus is called _______________

4) A nuclear particle that has no electrical charge is called ______________

5) The subatomic particles that are least massive and most massive, respectively

are the ________________ and .________________

6) A cathode ray produced in a gas-filled tube is deflected by a magnetic field. A wire

carrying an electric current can be pulled by a magnetic field. A cathode

ray is deflected away from a negatively charged object. What property of the

cathode ray is shown by these phenomena?

_______________________________________________________________

7) How would the electrons produced in a cathode-ray tube filled with neon gas

compare with the electrons produced in a cathode-ray tube filled with chlorine gas?

_______________________________________________________________

_______________________________________________________________

_______________________________________________________________

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8 ) a) Are atoms positively, negatively, or neutrally charged?

_______________________________________________________________

b) Explain how an atom can exist in this state.

_______________________________________________________________

9) Compare the THREE subatomic particles in terms of locations in the

atom, mass, and relative charge. P.79

locations in the

atom

mass relative charge

e -

p +

n 0

C) SHORT ANSWER: COUNTING ATOMS: p. 80- 83

1- Explain the difference between the:

a) Mass number b) Atomic number c) Isotopes

_______________________________________________________________

_______________________________________________________________

_______________________________________________________________

_______________________________________________________________

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2- Draw the THREE “Hydrogen” isotopes atoms: Protium - Deuterium - Tritium

3- Use a periodic table to complete the following chart: (write the Symbol):

Element Symbol Atomic number Mass number

Europium-151 Eu 63 151

Silver -109 Ag 47 109

Tellurium-128 Te 52 128

4- List the number of protons, neutrons, and electrons found in (Zinc- 66): Zn30

_______ mass number Atomic number _____

_______ protons

_______ electrons

_______ neutrons

GOOD LUCK!

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Name: ………….……………… Grade 9 ( )

Revision sheet for Final Exam

ANSWER KEY

Grade (9)

Chemistry

Term2

2019-2020

Materials for the Exam, you should Study from:

Chapter(3)

Lesson(1) The Atom Theory

Lesson(2) The structure of the Atom

Lesson(3) Counting Atoms

Interactive Book: Pages ( 69 – 83 )

The Revision sheet

NGSS: HS-PS1.A.1

HS-PS1.A.2

9 P a g e


A) Answer these questions: ATOMS: THE BUILDING BLOCKS OF MATTER

1) Write the definition that illustrates the law of conservation of mass.

Mass is not created not destroyed during chemical reactions or physical changes.

2) State two principles from Dalton’s atomic theory that have been revised as

new information has become available.

1) Atoms of different elements combine in simple whole-number ratios to form

chemical compounds.

2) In chemical reactions, atoms are combined, separated, or rearranged.

3) The formation of water according to the equation 2H2 + O2 2H2O

Shows that 2 molecules (made of 4 atoms) of hydrogen and 1 molecule (made of 2

atoms) of oxygen produce 2 molecules of water. The total mass of the product, water,

is equal to the sum of the masses of each of the reactants, hydrogen and oxygen.

1-What parts of Dalton’s atomic theory are illustrated by this reaction?

2-What law does this reaction illustrate?

1) Atoms of different elements combine in simple whole-number ratios to form

chemical compounds.

2) Law of conservation of mass: Mass is neither created nor destroyed during

ordinary chemical reactions or physical changes, which means: The total mass of the

products was always equal to the total mass of the reactants.

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4) List the 3 Laws of Atomic Theory? P.70

1) Law of conservation of mass : Mass is neither created nor destroyed during

ordinary chemical reactions or physical changes.

2) Law of definite proportions: A compound contains the same elements in exactly

the same proportions regardless of sample size or source of the compound.

3) Law of multiple proportions: If two or more compounds are composed of the

same two elements, then the ratio of the masses of the second element combined with

a certain mass of the first element is a ratio of small whole numbers.

5) Write the definition of Law of definite proportions ? P.70

A compound contains the same elements in exactly the same proportions regardless of

sample size or source of the compound.

6) PROBLEMS:

Write the answer: Show all your work in the space provided:

3) If 3 g of element C combine with 8 g of element D to form compound CD.

How many grams of D are needed to form compound CD2?

……… C + D CD

3g 8g

……… C + 2D ? CD2 ( 8 g x 2 =16 g)

4) Complete the following equations:

C + O …… CO ……

CO ….. C ……+ …. O ….

C + O + O …… CO2 ……

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3) A sample of baking soda, NaHCO3, always contains 27.37 % by mass of

Sodium, 1.20 % of hydrogen, 14.30 % of carbon, and 57.14 % of oxygen.

a. Which law do these data illustrate?

Law of multiple proportions.

b. State the law.

If two or more compounds are composed of the same two elements, then the ratio of

the masses of the second element combined with a certain mass of the first element is

a ratio of small whole numbers

7) CHOOSE THE RIGHT ANSWERS:

1. The protons and neutrons are located in the ……… of the atom.

a. center b. orbits

c. outside d. none of the above

2. The negative charged disk in the electrical analysis is called……:

a. cathode b. water

c. solution d. anode

3. Atoms contains ……………… particles:

a. positive b. negative.

c. positive and negative d. neutral

8) Nitrogen and oxygen combine to form several compounds, as shown by the

following:

Compounds Mass of nitrogen that combines with 1 g oxygen

NO 1.70 g

NO2 0.85 g

NO4 0.44 g

Which law do these data illustrate?

Law of multiple proportions.

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B) SHORT ANSWER: THE STRUCTURE OF THE ATOM: p.74-79

Answer the following questions in the space provided.

1) In cathode-ray tubes, the cathode ray is emitted from the negative electrode,

which is called the __ cathode __

2) The smallest unit of an element that can exist either alone or in molecules

containing the same or different elements is the_______atoms___.

3 ) A positively charged particle found in the nucleus is called ___ proton__

4) A nuclear particle that has no electrical charge is called __neutron__

5) The subatomic particles that are least massive and most massive, respectively

are the __ electron __ and ___ neutron .___

6) A cathode ray produced in a gas-filled tube is deflected by a magnetic field. A wire

carrying an electric current can be pulled by a magnetic field. A cathode

ray is deflected away from a negatively charged object. What property of the

cathode ray is shown by these phenomena?

__ In cathode-ray tubes, the cathode ray is emitted from the negative electrode,

which is called the (cathode) and the particles are negatively charged.

7) How would the electrons produced in a cathode-ray tube filled with neon gas

compare with the electrons produced in a cathode-ray tube filled with chlorine gas?

The electrons produced from neon gas and chlorine gas would behave in the same

way because electrons form does not be different from element to element.

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8 ) a) Are atoms positively, negatively, or neutrally charged?

_________neutrally charged ________

b) Explain how an atom can exist in this state.

________ The Nucleus is Positive and Electron cloud is Negative _______

9) Compare the THREE subatomic particles in terms of locations in the

atom, mass, and relative charge. P.79

locations in the

atom

mass relative charge

e- In the orbits around the

nucleus 9.109 × 1 0 −31 - 1 , ( - ) ve

p+ In the nucleus OR

In the center of the atom 1.673 × 1 0 −27 + 1 , ( + ) ve

n 0 In the nucleus OR

in the center of the atom 1.675 × 1 0 −27 0

C) SHORT ANSWER: COUNTING ATOMS: p. 80- 83

1- Explain the difference between the:

b) Mass number b) Atomic number c) Isotopes

a) Mass number is: the total number of protons and neutrons that make up its

nucleus.

b) Atomic number is: of an element is the number of protons of each atom of

that element.

c) Isotopes: are atoms of the same element that have different masses.

Isotopes of an element have the same number of protons and electrons but a

different number of neutrons.

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2- Draw the THREE “Hydrogen” isotopes atoms: see p.81

Protium – Deuterium - Tritium

3- Use a periodic table to complete the following chart: (write the Symbol):

Element Symbol Atomic number Mass number

Europium-151 Eu 15163 63 151

Silver -109 Ag10947

47 109

Tellurium-128 Te 12852 52 128

4- List the number of protons, neutrons, and electrons found in (Zinc- 66): Zn30

____66___ mass number Atomic number ___30__

____30___ protons

____30___ electrons

____36___ neutrons ( 66 – 30 ) = 36

GOOD LUCK!

Revision sheet for Final Exam Grade (9) Chemistry Term2 ... · 5) Write the definition of Law of definite proportions ? P.70 A compound contains the same elements in exactly the same

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