Physical Science: Chapter 2 Study Guide
List 4 ways to detect that a chemical change has occurred.
-change of color -bubbling/fizzing -exploding -density
Physical properties
-color -density -magnetism -melting point -conducting electricity -boiling point
Chemical properties
-dissolving -reactivity -corrosion -flammability
Explain why elements and compounds are pure substances.
A compound can be destroyed and composed of two or more different atoms
Explain the different between a pure substance and a homogeneous mixture.
A pure substance is a element or compound. A homogeneous mixture has the same proportions.
Describe how the characteristic properties of a piece of ice are different from its other properties.
Becomes liquid, water or gas or water vapor
Explain how aluminum is a suitable material to use in making cans based on its physical and chemical properties.
It is very malleable and very flexible. It is also waterproof, and non reactant.
When the water is mixed with rubbing alcohol, the two liquids completely dissolve. Are the two liquids miscible, or they immiscible? Explain the difference between the two terms.
They are miscible because miscible is being mixed together and immiscible is making layers.
Compare physical changes and chemical changes.
They both change the physical properties of a substance.
When sugar is added to water, the sugar dissolves and the resulting liquid is clear. Do the sugar and water from a pure substance, or do they form a mixture? Explain your answer.
They form a mixture because the water is sweet now.
When wood is burned, new substance are produced, Describe this reaction, and explain what type of change occurs. Use the terms flammability, chemical property, physical change or chemical change.
When wood burns it has a physical change when it turns into ash. It also changes the chemical property when there is ash in the air. The flammability changes when the ashes run out.
Explain why baking is a chemical change.
You are creating a new substance. You cant change it back to its original state.
Explain why dissolving is a physical change.
You aren't burning it and it does back to its original state.
Physical change
a change of matter from one form to another without a change in chemical properties
Chemical change
a change that occurs when one or more substances change into entirely new substances with different properties
Mixture
a combination of two or more substances that are not chemically combined
Molecule
a group of atoms that are held together by chemical forces
a pail of sand and water is
a heterogeneous mixture
sea water is
a heterogeneous mixture
air is
a homogeneous mixture
banana split is
a homogeneous mixture
chocolate syrup is
a homogeneous mixture
human blood is
a homogeneous mixture
Which of the following is an example of a chemical change? gasoline evaporating sugar dissolving in water a metal surface rusting a mixture separating into its components
a metal surface rusting
Pure Substance
a sample of matter, either a single element or a single compound, that has definite chemical and physical properties
Compound
a substance made up of two or more different elements joined by chemical bonds
Element
a substance that cannot be separated or broken down into simpler substances
Compare and contrast atoms and molecules
an atom has one molecule and a molecule has more than on nucleus
Matter
anything that has mass and takes up space
What is matter?
anything that takes up space and has mass
Classify each of the following as a physical or chemical property of phosphorus: It burns in air
chemical
Classify each of the following as a physical or chemical property of sulfur: It combines with oxygen
chemical
Classify each of the following as a physical or chemical property of sulfur: It reacts with hydrogen to form a gas
chemical
chemical or physical change: burning propane
chemical
chemical or physical change: burning wood
chemical
chemical or physical change: cooking
chemical
Classify each of the following as an element or a compound: acetylene, C₂H₂
compound
Classify each of the following as an element or a compound: aspirin, C₉H₈O₄
compound
Classify each of the following as an element or a compound: benzene, C₆H₆
compound
Which of the following terms most accurately describes carbon dioxides? element compound mixture solution
compound
Compute the density of an 820 g sample of pure silicon occupying a 350 cm³ container.
d= m/v d= 820 g/ 350 cm³ d= 2.34 g/cm³
What is the formula for density?
d=m/v v=m/d m=d x v
Classify each of the following as an element or a compound: titanium, Ti
element
Classify each of the following as an element or a compound: zinc, Zn
element
Classify each of the following as an element or a compound: aluminum, Al
element
If you add oil to water and shake the liquid, you will form a
heterogenous mixture
Calculate the mass of a sample of pure silver (density = 10.49 g/cm³) that has a volume of 12.99 cm³
m=d x v m= 10.49 g/cm³ x 12.99 cm³ m= 136.2 g/cm
Which of the following is an example of a physical change? melting ice cubes burning paper rusting iron burning gasoline
melting ice cubes
Determine which of the following are pure substances and which are mixtures: an egg yolk
mixture
Determine which of the following are pure substances and which are mixtures: honey
mixture
Determine which of the following are pure substances and which are mixtures: salt water
mixture
Classify each of the following as a physical or chemical property of phosphorus: It has a density of 1.82 g/cm³
physical
Classify each of the following as a physical or chemical property of phosphorus: It is a white, waxy solid
physical
Classify each of the following as a physical or chemical property of phosphorus: Its boiling point is 280.3°C
physical
Classify each of the following as a physical or chemical property of phosphorus: Its melting point is 44.1°C
physical
Classify each of the following as a physical or chemical property of sulfur: It is a yellow solid
physical
Classify each of the following as a physical or chemical property of sulfur: Its density is 2.97 g/cm³
physical
Classify each of the following as a physical or chemical property of sulfur: Its melting point is 112°C
physical
chemical or physical change: bending a metal rod
physical
chemical or physical change: breaking glass
physical
chemical or physical change: painting wood
physical
Determine which of the following are pure substances and which are mixtures: ammonia, NH₃
pure substance
Determine which of the following are pure substances and which are mixtures: isopropyl alchohol, C₃H₈O
pure substance
Determine which of the following are pure substances and which are mixtures: mercury, Hg
pure substance
compounds and elements are
pure substances
which of the following is a pure substance? grape juice saltwater table salt gasoline
table salt
Reactivity
the capacity of a substance to combine chemically with another substance
The photograph shows magnesium burning in the presence of oxygen. Give some evidence that a chemical change is occurring.
the magnesium that is burning is changing color
Density
the ratio of the mass of a substance to the volume of the substance
Atom
the smallest unit of an element that maintains the chemical properties of that element
Boiling Point
the temperature and pressure at which a liquid becomes a gas
Which of the following is a mixture? air salt water sulfur
water