science test
How many elements are found in the following chemical equation?K + Cl → KCl
2
Which of the following is true about mixtures and compounds?
A mixture contains different substances that are not chemically combined with one another.A compound forms when different substances chemically combine to form a new substance.Mixtures and compounds are both made of two or more different substances.
Which of the following is true about density and states of matter for most substances?
A substance is denser as a solid than as a gas.
Which of the following is a compound?
CO
An apple is placed on a kitchen counter. How could the movement of the particles in the apple be decreased?
Put it in the refrigerator.
Ocean water has a salinity of approximately 35,000 parts per million or 3.5%. What are the solute and solvent in ocean water?
Salt is the solute. Water is the solvent.
Federico has two samples of pure water—sample X and sample Y. Sample X has a volume of 1 L, and sample Y has a volume of 10 L. How do the boiling points of these two samples compare?
Sample X and sample Y will boil at the same temperature.
Water is a compound that is made out of two hydrogen atoms and one oxygen atom. Which statement about water is true?
Water has a set of properties that are different from oxygen and hydrogen.
NH3 is an example of
a compound.
Salt water is best described as _______.
a mixture
An individual with an excellent sense of smell is handed a bottle of perfume. After smelling the perfume, he reports that the perfume contains a predominant smell of roses with a faint touch of vanilla. If the perfume is made from water, rose essence, and a splash of vanilla, it is most likely
a mixture.
The element oxygen, represented by the symbol O, is classified as
a pure substance.
Why is water sometimes called the universal solvent?
because many substances dissolve in water
The temperature at which a substance in the liquid phase transforms to the gaseous phase refers to the substance's _______.
boiling point
What defines a mixture?
can be broken down into its basic substances through physical means
Carbon (C) and hydrogen (H) are pure substances. Each is made of only one type of atom, but carbon atoms are different from hydrogen atoms. Carbon and hydrogen chemically combine to form methane (CH4).
carbon and hydrogen are elements and methane is a compound.
What is the solute found in carbonated beverages that gives them their bubbly taste?
carbon dioxide
The chemical combination of two or more different atoms in fixed amounts is called a(n)
compound.
Which is a substance made up of only one kind of atom?
element
A 10 g sample of butter will melt at a temperature that is _______ the melting point of a 5 g sample of butter.
equal to
What is the term for the amount of space occupied by an object?
volume
The melting and boiling points of a substance are independent of
volume, mass, rate of heat change.
Apple juice is an example of a solution in nature. What is the solvent in apple juice?
water
True or false. Gas particles never touch each other.
False; gas particles can touch each other when they collide.
Which of the following statements is false?
Two or more different atoms combine chemically to form an element.
Which of the following is an example of a mixture?
the atmosphere
Which of the following is true about elements?
Elements combine to form compounds in organisms and nonliving substances.
Katlyn makes a gelatin dessert. She pours hot water into the flavored gelatin powder and stirs. What are the solute and solvent in this solution?
Gelatin powder is the solute. Water is the solvent.
Why does a balloon filled with helium rise while a balloon filled with an equal volume of average atmospheric air does not?
Helium has a lower density than air.
Hydrogen is a pure substance represented by the chemical symbol H. Which of the following best describes hydrogen?
Hydrogen is an element made of only one kind of atom.
If the average movement of the particles in a sweater increases, what will happen to the sweater's temperature?
It will increase.
Which statement about water as a solvent is true?
Some solids, liquids, and gases can dissolve in water.
When you heat the air inside a hot air balloon, it rises. Why does this occur?
The hot air inside the balloon becomes less dense than the air outside the balloon.
In which of the following states of matter are the particles close together but loosely connected so they can flow?
liquids only
The amount of matter in an object is its ________.
mass
Anything that takes up space and has mass is __________.
matter
Which physical property refers to the temperature at which a substance in a solid state transforms to a liquid state?
melting point
Sharon pours salt into a glass of water. The salt dissolves. The substance in the glass is a(n) __________.
mixture
The air we breathe contains different individual gases (mostly nitrogen and oxygen). Which of the following correctly describes the air we breathe?
mixture
Steve puts some cheddar cheese in a pan on the stove and starts to melt it. After a little while, there is a layer of oil floating on top of the cheese. From the way the cheese melted, Steve knows it is a
mixture.
Look at the graph above showing the composition of air. Which component is the solvent?
nitrogen
Which of the following is a solution?
ocean water
Water is a very unique substance because it can exist in all three phases of matter (solid, liquid, gas) within the normal temperature ranges found on Earth.When one observes the phase of matter of water, one observes a property of matter.
physical
When the components of a mixture are uniformly mixed together, the mixture is called a solution.Ocean water is a solution of water and _______.
salt
Which of the following states of matter has a definite volume?
solids and liquids only
Matter can exist in different phases or states. What are three common states of matter?
solids, liquids, and gases