Chapter 2: The Components of Matter

Question 1

anion

Answer 1

A negatively charged ion.

Question 2

atom

Answer 2

The smallest unit of an element that retains the chemical nature of the element. A neutral, spherical entity composed of a positively charged central nucleus surrounded by one or more negatively charged electrons.

Question 3

atomic mass

Answer 3

(also atomic weight) The average of the masses of the naturally occurring isotopes of an element weighted according to their abundances.

Question 4

atomic mass unit (amu)

Answer 4

(see also dalton, Da) A mass exactly equal one-twelfth the mass of a carbon-12 atom.

Question 5

atomic number (Z)

Answer 5

The unique number of protons in the nucleus of each atom of an element (equal to the number of electrons in the neutral atom). An integer that expresses the positive charge of a nucleus or subatomic particle in multiples of the electronic charge.

Question 6

binary covalent compound

Answer 6

A compound that consists of atoms of two elements, typically nonmetals, in which bonding occurs primarily through electron sharing.

Question 7

binary ionic compound

Answer 7

A compound that consists of the oppositely charged ions of two elements.

Question 8

cathode ray

Answer 8

The ray of light emitted by the cathode (negative electrode) in a gas discharge tube; travels in a straight line, unless deflected by magnetic or electric fields.

Question 9

cation

Answer 9

A positively charged ion.