Science Exam 1 Review
which one is a physical change?
evaporation and sublimation
One cup of water is left outside for two days when it was checked there was only half a cup left. What happened?
evaporation; physical change
Boiling is a chemical change. true or false
false
Brady lit a match and said it was a physical change. true or false
false
melting is a chemical change. true or false
false
Will an object with a density of 0.999 sink or float in water?
float
Baking soda and vinegar are mixed,and immediately there are bubbles and fizzing. What does this show?
formation of a gas
Which of the following is a sign that a chemical reaction has occurred? change in shape, melting, formation of a gas, or dissolving
formation of a gas
What is the production of a precipitate?
formation of solid particles out of a liquid
Which of these would be correct to put at the end of a density answer?
g/ml
Which of the following IS a physical change? Getting a haircut, Rusty metal, sour milk, a compound
getting a hair cut
Which lab tool might you use to measure the volume of a liquid?
graduated cylinder
Helium balloons rise on earth because
helium is less dense than air
A brick sinks in water while a wooden block of the same size floats. This is because the brick has a
higher density than the wooden block
what happens when water freezes?
ice is formed; physical change
A can of Coke will sink in a bowl of water. A can of Diet Coke will float in a bowl of water. What does this tell you about the density of the Diet Coke?
it is smaller than 1
Which of the following properties is a physical property? magnetism, reactivity with oxygen, flammability, non-reactive
magnetism
The density of Prof. Tesfay can be measured using which of these quantities?
mass and volume
Which of the following is NOT a physical property? breaking a window, color, density, or freezing point
breaking a window
A man going camping chops a log to make firewood. Then he burns the firewood to roast his marshmallows.Which of these activities demonstrated a chemical change?
burning the firewood
A half-eaten apple turns brown. How do we know that this is a chemical change?
change in color
what is the definition of physical change?
changes affecting the form of a chemical substance, but not its chemical composition.
If a student is combining two substances and sees bubbles and fizzing, a ______ is probably taking place.
chemical
Is bleaching your hair a physical or chemical change?
chemical
Is burning wood a chemical or physical change?
chemical
Is moldy cheese a chemical or physical change?
chemical
Adding baking soda and vinegar together and it fizzes and creates carbon dioxide is a
chemical change
Discoloration of a coin is a
chemical change
Green bananas turning yellow on their own as they ripen is a
chemical change
Photosynthesis is an example of a
chemical change
The smell your dog makes after eating to much people food is a
chemical change
When elements bond together, this results in a
chemical change
what is burning?
chemical change
what is digestion?
chemical change
What kind of properties can only be observed when a substance changes into a different substance?
chemical properties
what is solubility?
chemical property
A student stirs two liquids together and they turn into a solid. What type of change has happened and why?
chemical, because a new substance was formed
What Brady do to an egg for a chemical change.
cook the egg
Which is a chemical change? freezing fruit juice, slicing a potato, boiling water, or copper metal turning green
copper metal turning green
The following liquids are poured together in a beaker: alcohol (density=0.79), corn syrup (density=1.38), water (density=1.0), and cooking oil (density=0.93). Which of these liquids will sink to the bottom of the beaker?
corn syrup
Which property of matter is determined by dividing its mass by its volume?
density
What is the formula for density?
density = mass / volume
Which of the following IS a chemical change using chalk, water freezing, slicing cheese, digestion
digestion
Someone accidentally dropped a test tube on the floor and it shatters. Is this an example of a chemical change?
No, because the identity of the glass wasn't altered
I have two objects with the same volume but different masses. Which object will be more dense?
The object with more mass.
which one is the definition of chemical property?
a property or characteristic of a substance that is observed during a reaction where the chemical composition of a substance is changed
What is a precipitate?
a solid forms when one liquid is poured into another
Which of these would indicate that a new substance has been formed? a substance changed color, the volume of a substance increased, a solid became a liquid
a substance changed color
which one is a chemical property? odor, combustibility, solubility, or all of the above
all of the above
what is the definition of chemical change?
any change that results in the formation of new substances.
The tool used to measure the mass of a substance or object is a ______________.
balance
An object with which of the following densities will float on water? 0.7 g/cm3, 1.2 g/cm3, 3.5 g/cm3, or 11.4 g/cm3
0.7 g/cm3
What is the density of a liquid that has a mass of 27g and a volume of 30ml?
0.9 g/ml
What is the density of water?
1 g/ml
Veal finds a gold colored rock in a river. It has a mass of 9.65 grams and a volume of 0.5 cm3. What is the density of the rock?
19.3 g/cm3
A student mixes two clear liquids and sees the production of a bright yellow precipitate. How many indications are there of a chemical change?
2
Frank has an eraser. It has a mass of 4g, and a volume of 2cm3. What is its density?
2 g/cm3
A block has a mass of 54g and a volume of 20cm3. What is the density of the block?
2.7 g/cm3
A student mixes two chemicals and sees the production of bubbles, the formation of a precipitate, a change in shape, and heat being produced.How many of these observations indicate a chemical change?
3
Frank has a paper clip. It has a mass of 9g and a volume of 3cm3. What is its density?
3 g/cm3
What is the density of a substance that has a mass of 30g and a volume of 6 liters?
5 g/l
Jack has a rock. The rock has a mass of 14g and a volume of 2cm3. What is the density of the rock?
7 g/cm3
Find the density of a 2 cm x 2 cm x 2 cm cube with a mass of 64 g.
8 g/cm3
A piece of copper has a mass of 89g and a volume of 10 cm3. What would be the density of the copper?
8.9 g/cm3
A student has baking soda, sugar,and vinegar. What should he do if he wants to see a chemical reaction? Stir the baking soda and sugar together and notice the color, Add the sugar to the vinegar and watch it dissolve, Add the baking soda to the vinegar and watch for bubbles
Add the baking soda to the vinegar and watch for bubbles
You know you a chemical reaction has occurred if there is a precipitate. there is a color change, there is a temperature change, All of these answers are evidence.
All of these answers are evidence.
One of the signs of a chemical reaction taking place is: Bubbles are produced, Reactants are not combining, Products are not forming, Color is not changing
Bubbles are produced
Which is a Chemical property? Thermal Conductivity, Density, Malleability, or Flammability
Flammability
A student mixes two clear liquids and the mixture slowly turns orange.Which conclusion can we draw about the clear liquids?
They formed a new substance
A student mixes a white powder with a clear liquid and the liquid turns cloudy white. What can we conclude about the powder and the liquid?
They underwent a physical change
Someone puts a water bottle in the freezer and it turns to ice. Is this an example of a physical change?
Yes, because a new substance was not formed.
Which units of measurement are used for volume?
milliliter
In chemical reactions, the law of conservation of mass is...... disobeyed, not true, obeyed, or used sometime
obeyed
Is hammering wood together to build a house a chemical or physical change?
physical
Is melting butter for popcorn a chemical or physical change?
physical
Someone takes a piece of fabric and cut it up into lots of small pieces. Is this a chemical change or a physical change?
physical
A change in the size, shape, or state of matter.
physical change
Kim puts an ice cube in a beaker and it melts. This is a good example of:
physical change
Using dye to change the color of a shirt green.
physical change
When you break a cracker into pieces it is a
physical change
Which type of change is easier to reverse?
physical change
what is condensing?
physical change
Someone boils water until it evaporates. What kind of change has happened and why?
physical, because a new substance was not formed
A scientist has four different liquids and pours them all into a bottle. The silver liquid sinks to the bottom, the red liquid settles on top of the silver one, and the pink liquid stays at the surface. Which liquid has the smallest density?
pink liquid
Exothermic reactions...
release energy
During a chemical change, a student notices the production of heat. What does this indicate?
release in energy
which one is a chemical change? density, color, or respiration
respiration
Will an object with a density of 1.01 g/cm3 float or sink?
sink
Which of the following is NOT an example of a physical change? crumpled paper, pencil sharpening, shrunken clothing, or sour milk
sour milk
Which of the following is NOT evidence that a new substance has been formed? change in color, production of a gas, or stirring 2 substances together
stirring 2 substances together
density
the degree of compactness of a substance.
At the end of chemical reactions, what is the total mass of the reactants compared to the total mass of the products?
the mass is the same
A student has two 100 mL beakers of different clear liquids, both at room temperature. The student mixes them. Which of these reactions would NOT show a chemical change? The mixture's volume is 200 mL., The mixture turns blue., The mixture heats up.
the mixture's volume is 200 mL.
The Law of Conservation of Mass proves that
the number of atoms in a chemical reaction does not change
Why do ice cubes float in a glass of water?
the water is more dense than the ice cubes
Why do some substances float on water?
they are less dense than water
Matter is never destroyed or created in chemical reactions. true or false
true
True or False: The density of a specific type of material never changes.
true
energy is a chemical property. true or false
true
what stays the same when there is a physical change? density, volume, neither
volume
