Chapter 6

Question 1

acid rain

Answer 1

rain water that has a pH below 7; caused by emissions of sulfur dioxide, nitrogen oxide, and other pollutants.

Question 2

atomic number

Answer 2

the number of protons in the nuclei of the atoms of a particular element; the elements are listed in the periodic table of the elements according to atomic number.

Question 3

chemical formula

Answer 3

an expression of the elements in a compound and their ratios in which the elements are denoted by their chemical symbols.

Question 4

chemical symbol

Answer 4

the symbol for one of the 118 elements listed in the periodic table of the elements.

Question 5

compound

Answer 5

two or more different elements chemically bonded together.

Question 6

crystal

Answer 6

the atomic structure of a substance held together by ionic bonds, characterized by the orderly arrangement of atoms in a rigid lattice structure.

Question 7

crystal lattice

Answer 7

the structural frame work in which the atoms are arranged in a crystal.

Question 8

dissociate

Answer 8

when the ions in a crystal lattice come apart and go into a solution during the process of dissolving.

Question 9

dissolve

Answer 9

when a solute mixes with a solvent so that the particles of the solute and solvent are mixed together uniformly all the way down to the molecular level.

Question 10

element

Answer 10

a substance characterized by being composed of atoms all possessing the same number of protons in the nucleus.

Question 11

heterogeneous mixture

Answer 11

a mixture in which the presents of at least two different substances is visible to the eye, possibly with the aid of a microscope.

Question 12

homogeneous mixture

Answer 12

a mixture with a composition that is uniform all the way down to the molecular level. also called a solution.

Question 13

hydrocarbon

Answer 13

any molecule consisting of only hydrogen and carbon atoms. typically fossil fuels and other compounds derived from them.

Question 14

isotope

Answer 14

any variety of the atoms in an element, differing in the amount of neutrons in the nuclei of the atoms.

Question 15

metalloide

Answer 15

a group of seven elements located between the metals and the nonmetals in the periodic table, possessing some properties of both.

Question 16

mixture

Answer 16

a combination of substances that occurs without any chemical reaction. substances in the mixture retain their own properties and may be separated from one another by physical needs such as filtration and boiling.

Question 17

molecule

Answer 17

a chemically bonded cluster of atoms; the smallest particle in compounds formed by covalent bonding between nonmetals (including hydrogen.)

Question 18

the periodic table of the elements

Answer 18

the table listing all of the elements including atomic mass and number.

Question 19

polar

Answer 19

when the electrons in a molecule are not balanced, so one end or region of the molecule is more positively charged and another region is more negatively charged.

Question 20

pure substance

Answer 20

an element or compound

Question 21

solute

Answer 21

a solid liquid or gas that is dissolved into a fluid