Chemistry Exam 2

All matter is composed of _____________.

Atoms.

The atoms of a given element differ from the atoms of _____________.

Other elements.

Chemical compounds consist of _________________.

Two or more different elements bonded together.

Chemical reactions change only the way the atoms are _____________ in compounds; the _____________ are unchanged.

Combined; atoms.

Atoms are composed of tiny _____________ called _____________, _____________, and _____________.

Subatomic particles; protons, neutrons, electrons.

The masses of atoms and their constituent subatomic particles are very _____________ when measured in _____________.

Small; atomic mass units (amu).

Atomic masses are expressed on a _____________ scale.

Relative.

The basis for the relative atomic mass scale is an atom of ________________ that contains ________________ and ______________.

Carbon; 6 protons; 6 neutrons.

This carbon atom is assigned a mass of exactly _____________.

12 atomic mass units (amu).

Both protons and neutrons have a mass close to _____________.

1 amu.

Electrons are _____________ than protons and neutrons.

Much lighter.

Protons and electrons have _____________ that are equal in _____________ but opposite in _____________.

Charges; magnitude; sign.

The protons and neutrons are packed closely together in a dense core called the _____________.

Nucleus.

Surrounding the nucleus, the electrons move about rapidly through _____________.

Electron clouds.

Diameter of a nucleus is only about _____________.

1/100,000 of an atom.

Diameter of an atom is only about _____________.

1 angstrom (10^-10 m).

The structure of the atom is determined by interplay of _____________.

Forces.

Opposite electrical charges ____________ each other, like charges ____________ each other.

Attract; repel.

Protons and neutrons in the nucleus are held together by the _____________.

Strong nuclear force.

Atomic Number (Z): The number of _____________ in each atom of an element.

Protons.

All atoms of a particular element have the same number of _____________ in the nucleus.

Protons.

Atoms are _____________ overall and have no _____________ because the number of positively charged _____________ and the number of negatively charged _____________ are ____________ in each atom.

Neutral; charge; protons; electrons; equal.

Mass Number (A): The total number of _____________ in an atom.

Protons and neutrons.

Isotopes: Atoms with identical _____________ but different _____________ are called _____________.

Atomic numbers; mass numbers; isotopes.

Protium, deuterium, and tritium are three isotopes of the element _____________.

Hydrogen.

H, most abundant hydrogen isotope has _____________ proton and ___________ neutrons (Z= , A= ).

1; 0.

D, this heavy hydrogen isotope has ___________ proton and ______________ neutron (Z= , A= ).

1; 1.

T, this radioactive hydrogen isotope has ____________ proton and _____________ neutrons (Z= , A= ).

1; 2.

To calculate the atomic weight of an element, the ____________ and the ____________ of each naturally occurring isotope must be known.

Mass; abundance.

Ionic bond: The _____________ attractions between ____________ in a crystal.

Electrostatic; ions.

Ionic compound: A compound that contains _____________.

Ions.