SNC1/2D
Quiz #1
July 6, 2020
Reactions, Atoms, Bohr- Rutherford Diagram, compounds
Name: Paul Vo
_______________
Student I.D Number: #18039
Afternoon Class
Teacher: Mr. Arumugam______________________________________
Part 1 Physical/Chemical reactions:
a) State whether the reaction mentioned is chemical, physical or
both (if both, state which one is first). Justify your answer using
full sentences
Scenario
Physical or
Chemical
Change?
Proof, provide concrete examples from scenario
Chemical change
Grass growth is a chemical phenomenon because it is metabolized
by the environment to grow. It is no longer the same substance.
Chemical change
Black bread is in a long toaster because it's burnt. The black part
of bread is metabolized and it has been transformed into another
substance
Physical change
The paper only changed shape because it was folded into an
airplane. It is still the same substance
Chemical change
Silver tarnishes means the color of Silver is changing, indicating
that a change of substance is taking place. It is no longer the
original substance
Grass Grows
1.
2.
3.
4.
Your friend decides to
toast a piece of bread,
but leaves it in the
toaster too long. The
bread is black and the
kitchen if full of smoke.
Paper is folded into a
paper airplane
Silver tarnishes
Ice cube melts into a
glass of water
5.
6.
An apple is cut in half,
and begins to rot.
Physical change
The stone only flows into another form, water. But the substance
that made the stone is water remains unchanged
Chemical change
The apple is rot because it is turning to a new substance. It is no
longer the original substance
7.
A straight piece of wire
is coiled to form a new
spring
Physical change
The straight only changes shape, not the material that makes it. It
is still the same substance
8.
Chocolate syrup is
dissolved in a warm
glass of milk
Physical change
The chocolate syrup is dissolved because chocolate and milk are
putted together. However, chocolate and milk are still separate
substances
9.
10.
A bicycle is broken in
half and is left outside.
It begins to rust.
Mr.A bites into his
lunch, then begins to
digest it in his stomach
Physical change
&
Chemical change
Physical change
&
Chemical change
Physical change: Bicycle only changes shape when broken. It is
still the original subtace
Chemical change: the bike starts to rust because it is being
transformed into another substance. It is no longer the original
substance
Physics: Mr. He eats at lunch because the food only changes to
another shape. It remains the same substance.
Chemistry: When the stomach is digested, food is being converted
into another substance. It is no longer the original substance.
Part 2: What are the 3 subatomic particles of the atom? List their
charge and location of the atom. (9 marks)
Name of Particle
Charge
Location of Particle
Positive charge
Inside the nuceus
Netrally charged
Inside the nucleus
Protons
1.
Neutrons
2.
Electrons
Negatively charged
3.
Outside the nucleus, orbits around it
Part 3: Draw the Bohr- Rutherford diagram for the listed elements (3
marks)
Magnesium
Nitrogen
Potassium
Part 4: Define:
1) What are the differences between ionic and molecular
compounds? (4 marks, be specific)
A. Ionic compounds is made up by a metal and non – metal
putting together. Molecular compounds is made up by 2 or
more non – metals putting together
B. Ionic compounds has an ionic bond which is transfering of
electrons to form a new compound. Molecular compounds
share of electrons to form a new compound.
2) Why do we need to balance chemical equations? (2 marks)
We need to balance chemical equation because of the Law of
conservation of mass: states that in any given chemical reaction,
the mass of the reactants must equal the mass of the products.
3) Define AND state the diatomic elements covered in class (4
marks)
 Diatomic elements are elements that naturally form
compounds with itself.
 Hydrogen, Oxygen, Fluorine, Bromine, Iodine, Nitrogen and
Chlorine are Diatomic elements
4) Using your knowledge of bohr-rutherford diagrams explain why
the noble gases are the most “stable” (unreactive) elements. (3
marks)
Noble gases are the elements that the most “stable” because
their outer shell is already completely full.
For example:
Part 5: Calculate. Show all your work. Round your answer.
1) Calculate the neutrons in Magnesium (AM= 24.31, AN=12) (2
marks)
# of neutrons = atomic mass – atomic # = 24.31 – 12 = 12.31
2) An element has an atomic mass 32.07 and 16 neutrons. What is
this element? How do you know? (3 marks)
This is Sulfur. Because # of neutrons = atomic mass – atomic #.
Therfore, atomic # = atomic mass - # of neutrons = 32.07 – 16 ~ 16
The Sulfur’s Atomic number is 16.
3) An element has an atomic mass 19, and 10 neurons. What is this
element? How do you know? (3 marks)
This is Fluorine. Because # of neutrons = atomic mass – atomic #.
Therfore, atomic # = atomic mass - # of neutrons = 19 – 10 = 9
The Fluorine’s Atomic number is 9
Part 6. Which compound forms an ionic bond? If not, explain why. If
yes, draw the Bohr-Rutherford diagram of the ionic bond and state
which element is the cation and anion. How do you know? (12 marks)
NaCl
This is an Ionic
compound.
Mg F 2
This is an Ionic
compound.
H2O
This is not an Ionic compound because H and O have to share electron
to each other. This is a covalent compound.
Part 7: Write the name of :
1) (NH4)2S: Diammonium Sulfuride
2) Sn3P4: Tin (IV) Phosphoride
3) Cr2O3: Chromium (III) Oxide
4) Ni2S2: Nickel Sulfide
5) Si2Br6: Disilicon Hexabromide
Write the chemical formula of:
6) Nickel (III) oxide: N2O3
7) Copper (II) iodide: CuI2
8) Ammonium phosphide: (NH4)3PO4
9) Barium nitrate: Ba(NO3)2
10.Nitrogen trihydride: NH3
Part 8: Balance each equation (show ALL steps)
a) 2C2H6 + 7O2  4CO2 + 6H2O
This equation is already balanced.
b) Al + 3F2 2AlF3
c) C3H8 + O2  CO2 + H2O