Q2 PS Benchmark Review

Quarter 2

Physical Science

Benchmark Review

22-23 School Year

​Chemical Reactions

• ​Atoms rearrange

• ​Form new bonds

• ​Physical and chemical properties change

• ​New substance formed

Molecules and Atoms

• Matter is made up of molecules.

• Molecules are made up of small particles called atoms.

• Atoms are the smallest unit of matter.

• When 2 or more atoms combine they create molecules.

Atoms, Molecules and Compounds

• Matter that is only made up of one type of atom can be referred to as an element or molecule.

Element or Molecule

• ​1 type of atom, 1 color

Atoms, Molecules and Compounds

• Matter that is made up of two or more types of atoms bonded together may be referred to as a molecule or compound.

Molecule or Compound

• ​2 or more different types of atoms.

Extended Structure vs Simple

• ​Group of atoms that are held together by chemical bonds and act as a unit.

• Some molecules are made of different types of atoms that are attracted to each other to form extended structures.

• Oppositely charged atoms can bond together to form an extended structure.

Extended Structures

Simple Molecules

Patterns in Structures/Crystals

• ​Type of extended structure that creates a REPEATING pattern due to the type of bond between atoms.

​

Example: GREEN, purple, GREEN

Multiple Choice

Based on the image which of the following is the best claim that you can make?

• The extended structure shows a repeating pattern

• The simple structure shows a repeating pattern

• The extended structure shows atoms that are not attracted to each other

• The extended structure shows one type of atom

Multiple Select

Based on the image which of the following is the best claim that you can make?

• The extended structure shows a repeating pattern

• The simple structure that has one type of atom

• The simple structure shows atoms that are attracted to each other

• The extended structure shows one type of atom

Multiple Select

Based on the image which of the following are extended structures?

• A

• B

• C

• D

• E

Multiple Choice

The Law of Conservation of Mass tells us that the mass of the products must be _________ to the mass of the reactants.

• More than

• Less than

• Equal to

Multiple Choice

In a reaction A + B ----> C, reactant A has mass of 3g and reactant B has a mass of 9g. What is the mass of the product C?

• 3 g

• 6 g

• 12 g

• 14 g

Multiple Choice

In a reaction A + B ----> C, reactant A has mass of 5g and product C has 9g. How many grams does reactant B have?

• 4 g

• 5 g

• 9 g

• 14 g

Physical Change

In a physical change the appearance of the substance only changes, not the composition.

ex: Change of state, change of shape

Chemical Changes

 A chemical change occurs when the substance's composition is changed. A NEW SUBSTANCE IS ALWAYS CREATED DURING A CHEMICAL CHANGE.

Indicators of a Chemical Change

• Change in temperature

• Change in color

• Formation of bubbles/gas

• formation of a precipitate

​Endothermic vs. Exothermic

• ​Endothermic is the absorption of energy. The products will be cooler than the reactants.

• ​Exothermic is the release of energy. The products will be warmer than the reactants.

Multiple Choice

What are the signs of a chemical reaction?

Check all that are true.

• Odor

• Precipitate

• Gas

• All of the above

Multiple Choice

A scientist placed a sample of lithium into a container of water. The scientist observed the lithium floating and making a buzzing sound as gas bubbles were forming around it. The temperature increased and the lithium was no longer present. Which conclusion is BEST supported by this observation?

• A chemical change took place.

• The lithium was dissolved by the water.

• Dissolved gases were released.

• Water was vaporized.

Multiple Choice

How does the concept of conservation of mass apply to chemical reactions?

• The reactants and products have exactly the same atoms.

• The reactants and products have exactly the same molecules.

• The change in the amount of matter is equal to the change in energy.

• The change in the amount of matter is only a small percentage of the total mass.

Multiple Choice

Which is the BEST evidence that a chemical change has occurred?

• change of state

• release of energy

• temperature change

• formation of a new substance

Multiple Choice

Which of the following is a example of physical change ?

• burning of wood

• photosynthesis

• melting of ice-cream

• ripening of fruit

Multiple Choice

Chemical or Physical? Glass breaking into tiny shards

• Chemical Change

• Physical Change

Multiple Choice

Any change in the state of matter of a substance is a...

• Physical Change

• Chemical Change

Multiple Choice

Evidence of a physical change.

• New substance

• Shape Change

• Light produced

• Gas released.

Multiple Choice

Which type of change are irreversible?

• Chemical Changes

• Physical Changes

• Changes in State

• Changes in Temperature

Multiple Choice

Identify what type of change happening in the picture below...

• Chemical Change

• Physical Change

• Endothermic Reaction

Match

Match the following

• Change of State (A)

• Acidity (A)

• A bike rusting (B)

• Paper torn into small pieces (B)

Physical (A)

Chemical (A)

Chemical (B)

Physical (B)

• Physical (A)

• Chemical (A)

• Chemical (B)

• Physical (B)

​Therefore... all chemical equations should be balanced in order to represent a chemical reaction.

​Balanced vs. Unbalance Equations

• ​Reactants-LEFT side of equation

• ​Products-RIGHT side of the equation

• ​Coefficients-identify how many groups

• ​Subscripts-identify how many elements

​

Steps

• Identify the elements (Capital Letters)

• ​Count how many of each

• ​SAME Elements SAME Number=BALANCED

Drag and Drop

The breaking and forming of new ​

Placeholder

results in the formation of ​

Placeholder

substances

The ​

Placeholder

makeup of the new substance is different from the ​

Placeholder

one

Drag these tiles and drop them in the correct blank above

bonds

new

chemical

original

physical

organic

atoms

Multiple Select

Zn + S → ZnS What are the reactants?

• Zn

• ZnS

• S

Multiple Choice

4NH₃ + 5O₂ → 4NO + 6H₂O

• Balanced

• Unbalanced

Multiple Choice

Al + Cl₂ → AlCl

• Balanced

• Unbalanced