Elements, Mixtures, Compounds (QUIZ 2) Flashcards
Which is classified as an element?
A) carbon dioxide
B) iron
C) vinegar
D) water
B) iron
Which is a compound?
A) sodium
B) sugar
C) nitrogen
D) air
B) sugar
Identify the INCORRECT statement.
(a) Helium in a balloon: an element.
(b) Paint: a mixture.
(c) Tap water: a compound.
(d) Mercury in a barometer; an element.
(c) Tap water: a compound.
Pure water is a compound while tap water consists of various components not just pure water.
An unused flashbulb contains magnesium and oxygen. After use, the contents are changed to magnesium oxide but the total mass does not change. This observation can best be explained by the
(a) Law of Constant Composition.
(b) Law of Multiple Proportions.
(c) Avogadro’s Law.
(d) Law of Conservation of Mass.
(d) Law of Conservation of Mass.
Which of the following is a suspension?
A) pure gold
B) pure oxygen
C) salt water
D) dusty air
D) dusty air
A suspension is a mixture in which the distributed particles are larger than those of the solvent and in which the particles, in time, will settle out.
When a solute is dissolved in a liquid solvent, the freezing point of the solution is lower than the freezing point of the pure liquid. In which of the following situations is this property of liquid solutions applied?
A) Sugar dissolves in water more quickly if the solution is heated.
B) Antifreeze added to water in a car’s radiator lowers the freezing point below zero degrees Celsius.
C) The oil and vinegar in salad dressing is mixed more thoroughly by shaking.
D) Spherical ice “cubes” freeze more quickly than regular ice cubes do.
B) Antifreeze added to water in a car’s radiator lowers the freezing point below zero degrees Celsius.
Which statement is false?
A) Water changes state at temperatures typical on Earth.
B) Frozen water is denser than liquid water.
C) Water is a unique substance on Earth.
D) Water is Earth’s most common solvent.
B) Frozen water is LESS dense than liquid water.
Ambient air is a _____.
A) element
B) compound
C) mixture
D) energy
C) mixture
Which of the following is not a compound?
A) HCl
B) Cl
C) NaCl
D) CO
B) Cl
Ambient air, steel, clear salt-water are ALL examples of:
A) homogeneous mixtures
B) heterogeneous mixtures
C) compounds
D) none of the above
E) all of the above
A) homogeneous mixtures
Tossed salad, granite, and iced tea are ALL examples of:
A) homogeneous mixtures
B) heterogeneous mixtures
C) compounds
D) none of the above
E) all of the above
B) heterogeneous mixtures
What is made up of two or more elements that are chemically combined?
A) element
B) compound
C) mixture
D) solids
B) compound
Mixtures are _____ combined.
A) chemically
B) physically
C) spontaneously
D) thoroughly
B) physically
How can a scientist safely tell whether an unknown solution is a combination of salt and water, or sugar and water?
A) taste the solution
B) smell the solution
C) test the electrical conductivity of the solution
D) filter the solution
C) test the electrical conductivity of the solution
At constant temperature, as external pressure decreases, the boiling point _____.
A) increases (negative correlation)
B) decreases (positive correlation)
C) remains the same
B) decreases (positive correlation)
Adding a solute to a solvent _____ the freezing point and _____ the boiling point.
A) lowers, lowers
B) raises, raises
C) lowers, raises
D) lowers, raises
C) lowers, raises
Table sugar is an example of _____.
A) mixtures
B) compounds
C) elements
B) compounds
_____ is a pure substance?
A) bread
B) garden soil
C) table salt
D) seawater
C) table salt
A mixture that appears to be evenly mixed throughout:
A) an atom
B) a homogeneous mixture
C) a compound
D) a heterogeneous mixture
B) a homogeneous mixture
_____ is used to separate a solid from a liquid in which it is suspended.
A) filtration
B) suspension
C) distillation
D) colloidization
A) filtration
_____ is a mixture in which particles will settle out.
A) suspension
B) compound
C) colloid
D) distillation
A) suspension
Which is not a pure substance?
A) milk
B) water
C) oxygen
D) carbon dioxide
A) milk
Which substance is a compound?
A) copper
B) saltwater
C) magnesium
D) water
D) water
Which one of three words matches the three substances carbon dioxide, coal, carbon?
A) element, mixture, compound
B) compound, element, mixture
C) mixture, compound, element
D) compound, mixture, element
D) compound, mixture, element
_____ have no fixed boiling point.
A) Elements and mixtures
B) Mixtures
C) Elements and compounds
D) Compounds
B) Mixtures
Which is likely to consist of one element?
A) pure quartz crystal
B) stainless steel
C) bronze statue
D) yellow rock sulfur
D) yellow rock sulfur
Which element is a very soft silvery solid metal at room temperature?
A) sodium
B) chlorine
C) aluminum
D) bromine
A) sodium
_____ have a definite chemical symbol or formula.
A) Elements and mixtures
B) Mixtures
C) Elements and compounds
D) Compounds
C) Elements and compounds
Which statement is usually true when comparing the physical properties of metallic and non-metallic elements?
A) Metals are poor conductors of heat.
B) Metals have high melting and boiling points.
C) Non-metals have high densities.
D) Non-metals are good conductors of electricity.
B) Metals have high melting and boiling points.
Which of these is an element?
A) alcohol
B) water
C) bromine
D) magnesium oxide
C) bromine
Which method of separation is best used for obtaining salt from seawater?
A) filtration
B) evaporation
C) chromatography
D) distillation
B) evaporation
Which is most likely to consist of one element?
A) brass rivet
B) pure quartz crystal
C) bronze statue
D) silver plate
D) silver plate
How to separate pebbles and water?
A) decantation
B) filtration
C) evaporation
D) sieving
D) sieving
How to separate noodles and water?
A) decantation
B) filtration
C) evaporation
D) sieving
D) sieving
How to separate meat and sauce.
A) decantation
B) filtration
C) evaporation
D) sieving
A) decantation
How to separate oil and water.
A) decantation
B) magnetic attraction
C) distillation
D) sieving
C) distillation
How to separate needles and toothpicks.
A) decantation
B) magnetic attraction
C) distillation
D) sieving
B) magnetic attraction
How to separate tea leaves and tea liquid.
A) decantation
B) magnetic attraction
C) distillation
D) sieving
D) sieving
How to separate coffee beans and coffee liquid.
A) distillation
B) evaporation
C) filtration
D) sieving
C) filtration
Which process separates blood cells and platelets?
A) centrifugation
B) distillation
C) decantation
D) evaporation
A) centrifugation
An unknown substance is a semi-conductor and is very brittle. This unknown substance could be which of the following elements from the table?
A) copper
B) boron
C) mercury
D) hydrogen
B) boron
An unknown substance takes the shape of its container and has a mirror-like luster. This unknown substance could be which of the following elements from the table?
A) mercury
B) hydrogen
C) boron
D) copper
A) mercury
An unknown substance is colorless and has a very low density. This unknown substance could be which of the following elements from the table?
A) mercury
B) hydrogen
C) boron
D) copper
B) hydrogen
An unknown substance is a very good conductor of heat and electricity and can be bent and shaped easily. This unknown substance could be which of the following elements from the table?
A) mercury
B) hydrogen
C) boron
D) copper
D) copper
