Chapter 17: Physical Science

of the four boxes shown above, which represent a pure elemental material?

A and C

In the boxes shown above, each solid circle represents an atom of the same element. How many different types of molecules are depicted in the above transformation?

B

of the four boxes shown above, which represents a pure compound?

B

basic research

a branch of scientific research that focuses on a greater understanding of how the natural world operates

applied research

a branch of scientific research that focuses on developing applications built upon the principles discovered through basic research

physical change

a change in which a substance changes one or more of its physical properties without transforming it into a new substance

chemical change

a change in which the atoms of one or more substances are rearranged into one or more new substances

compound

a material in which atoms of different elements are bonded to one another

elemental formula

a notation that uses the atomic symbol and sometimes a numerical subscript to denote how atoms of the element are bonded together

chemical formula

a notation used to indicate the composition of a compound, consisting of the atomic symbols for the different elements of the compound and numerical subscripts indicating the ratio in which the atoms combine

chemical property

a property that characterizes the ability of a substance to undergo a change that transforms it into a different substance

when the atoms of a material vibrate in a fixed three-dimensional state, the material is

a solid

molecule

a submicroscopic particle consisting of a group of atoms

condensation

a transformation from a gas to a liquid

freezing

a transformation from a liquid to a solid

melting

a transformation from a solid to a liquid

evaporation

a transformation to a liquid to a gas

physical property

any physical attribute of a substance, such as color, density, or hardness

most chemists focus on

applied research to provide us with new technology

the halogens

are all of the above

during a chemical change

atoms change partners to form a new material

the evaporation of a liquid is also called

boiling

is the following transformation representative of a physical change or chemical change?

chemical because the atoms are connected differently

which of the following causes a chemical change in a substance?

eating a slice of cheese

boiling

evaporation in which bubbles form beneath the liquid surface

molecules are of the microscopic realm

false

sodium chloride is toxic because of all the sodium metal it contains

false

the freezing of water is an example is a chemical change

false

Which phase of matter responds dramatically to changes in pressure?

gases

a compound is made of different kinds of atoms bonded together

in definite proportions

which of the following is classifies as nonmetal?

iodine

the circles in the boxes shown above represent the submicroscopic particles of a material in its three phases. From left to right these are

liquid, solid, and gas

solid

matter that has a definite volume and a definite shape

liquid

matter that has a definite volume but no definite shape, assuming the shape of its container

gas

matter that has neither a definite volume nor a definite shape, always filling any space available to it

are atoms made of molecules or are molecules made of atoms?

molecules are made of atoms

submicroscopic

refers to the realm of atoms and molecules, which is a realm so small that we are unable to observe it directly with optical microscopes

moving from left to right across any period of the periodic table, the atoms become

smaller in size

The number of different elements known to humankind are

somewhat more than 100

Molecules exist at what level?

submicroscopic

chemical reaction

synonymous with chemical change

heat of fusion

the amount of energy needed to change any substance from solid to liquid, which is the same amount of energy released when the substance transformation from a liquid to a solid

heat of vaporization

the amount of energy required to change any substance from liquid to gas, which is the same amount of energy released when the substance transforms from a gas to a liquid

chemical bond

the force of attraction between two atoms that holds them together

which of the following statements is true about compounds?

they are composed of different elements bonded together

a compound is made of atoms from different elements

true

another name for water is dihydrogen monoxide

true