Unit 3 Review 10/7/21

Unit 3 Review 10/7/21

by Amy Rethman

​8.5D Recognize that chemical formulas are used to identify substances and determine the number of atoms of each element in chemical formulas containing subscripts.

Compounds

We have a little less than 100 naturally occurring elements in the universe that we know of BUT we have so many different kinds of matter around us. Elements combine in limitless ways to form Compounds.

Multiple Choice

The ______ are numbers found on the lower right-hand side of an element symbol.

• Coefficient

• Exponent

• Multiplier

• Subscript

Multiple Choice

Coefficients in chemical formulas...

• Multiply just the first atom

• Add to the subscripts at the end of the molecule

• Multiply elements without subscripts

• Multiply EVERYTHING!

Multiple Choice

4CF₂Cl₂

• C = 4, F = 4, Cl = 2

• C = 1, F = 8, Cl = 8

• C = 4, F = 8, Cl = 8

• C = 1, F = 4, Cl = 8

Multiple Choice

H₂SO₄

• H = 2, S = 4, O = 4

• H = 2, S = 1, O = 4

• H = 8, S = 4, O = 4

• H = 2, SO = 4

Multiple Choice

How many different elements are in this formula?

• 5

• 4

• 20

• 10

Multiple Choice

How many CARBONs are in this formula?

• 1

• 4

• 8

• 12

Multiple Choice

How many total POTASSIUM atoms are in this formula?

• 8

• 2

• 4

• 12

Multiple Select

Which formulas have the same number of HYDROGENs?

Multiple Choice

Which formulas have the most number of HYDROGENs?

​Questions...clarification on formulas and counting atoms?????

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​Let's move on...

Physical Changes

• Matter changes appearance

• Atoms DO NOT REARRANGE

• Change of State - Boiling, Melting, Evaporativng

• Dissolving

• change in matter where the ATOMS rearrange and

• Form a NEW substance that wasn't there before

Chemical Changes

Multiple Choice

An object undergoes a physical change when it changes:

• color, burning, rusting

• shape, form, color

• tarnishing, melting, ashes

Multiple Choice

An object undergoes a chemical change when it changes:

• shape, form, state of matter

• melting, odor, size

• color, burning, rusting

Multiple Choice

When tearing a piece of paper, the mass will __________ because of the law of conservation of mass.

• increase

• decrease

• stay the same

Multiple Choice

Bubbles quickly appear and continue forming for 20 seconds and there are small amounts of the solid at the bottom of the liquid in the final observation.

• physical change

• chemical reaction

Multiple Choice

Water freezing into ice is an example of a...

• Physical Change
• Chemical Change

Multiple Choice

A change in which NEW substances are formed.

• Chemical change
• Physical change
• Casual change
• Formal change

Multiple Select

Check all the substances that are considered elements.

• gold

• water

• oxygen

• carbon dioxide

• silver

Multiple Select

Which of the following are compounds?

• Water

• H₂O

• Sugar

• Hydrogen

• CO₂

Multiple Choice

Which of the following is an example of a physical change?

• mixing baking soda and vinegar causing bubbles to form

• dissolving sugar into sweet tea

• heating sugar until it turns black

• letting milk spoil, forming a solid from a liquid

Multiple Select

Mark all the examples that result in a chemical change.

• Cooking / Baking

• Boiling Water

• Rusting

• Tearing food with teeth

• mixing food with saliva and enzymes to break it down into glucose

Multiple Select

Check all the examples of a chemical change.

• Formation of a solid out of a liquid

• fizzing and bubbling after two liquids are mixed

• Salt Dissolving in Hot water

• Food broken down in by saliva in the mouth and acid in the stomach

• Leaves turning brown

​Questions...clarification on changes?????

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​Let's move on....

Multiple Choice

When a roller coaster is at the top of a hill it has

• high potential energy

• high kinetic energy

• low potential energy

• equal amounts of kinetic and potential energy

Multiple Choice

When a roller coaster is at the bottom of a hill it has

• high potential energy

• high kinetic energy

• low kinetic energy

• equal amounts of kinetic and potential energy

Multiple Choice

Conservation of energy means that

• energy can be created but not destroyed

• energy can be destroyed but not created

• energy can both be created and destroyed

• energy can neither be created nor destroyed

Multiple Choice

Which is the best example that something has kinetic energy?

• a car parked on a steep hill

• a tennis ball rolling across the court

• a picture hanging on the wall

• a piece of coal before it's burned

Multiple Choice

Gravitational potential energy depends on the ________ and ________ of the object.

• Position (height) and mass

• Friction and movement

• Mass and Movement

• Height and Friction

Multiple Choice

When a pendulum swings, at which point is kinetic energy greatest?

• 1

• 2

• 3

• 4

Multiple Choice

In order to INCREASE the potential energy of an object, you need to:

• put the object lower to the ground

• raise the object higher

Multiple Choice

Where would this tossed baseball have the least amount of kinetic energy?

• point W

• point X

• point y

• point z

Multiple Choice

Explain what happens to the potential energy of a rock as it falls off the side of a cliff.

• The kinetic energy decreases as the potential energy increases.
• The kinetic energy decreases as the potential energy decreases.
• The potential energy decreases as the kinetic energy increases.
• The potential energy decreases as the kinetic energy decreases. 

​Questions...clarification on potential and kinetic energy?????

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​Let's move on....

Multiple Choice

Electrical Energy is transferred to _____ Energy.

• Solar
• Mechanical
• Chemical
• Electrical

Multiple Choice

When you eat pizza, Chemical Energy is transferred to _____ Energy.

• Solar
• Electrical
• Mechanical
• Chemical

Multiple Choice

Mechanical Energy is transferred to _____ Energy.

• Solar
• Mechanical
• Electrical
• Potential

Multiple Choice

The Electrical Energy of the stove is transferred to _____ Energy.

• Solar
• Thermal
• Potential
• Electrical

Multiple Choice

Which energy conversion is taking place when you put gasoline in a car?

• thermal -> electrical
• mechanical -> electrical
• chemical -> mechanical
• mechanical -> electromagnetic

Multiple Choice

A battery converts what type of energy to another?

• sound to kinetic
• light to heat
• mechanical to electrical
• chemical to electrical

Multiple Choice

A student listens to music with a digital music player, similar to the one shown below. Which best describes the energy transformations that take place in the music player?

• Mechanical to chemical to electrical
• Chemical to sound to electrical
• Chemical to electrical to sound
• Electrical to heat to sound

Multiple Choice

What kind of energy is represented in the picture?

• Thermal
• Chemical
• Sound
• Nuclear

Multiple Choice

Electrical -> Mechanical -> Sound 

• A triple beam balance measuring an object’s mass
• A pencil sharpener plugged into a wall outlet
• A projector displaying a diagram on the screen
• A working flashlight used to light up a dark corner