Atoms, Molecules, and Ions

Ionic compounds

________ tend to be composed of metals bonded to nonmetals.

Dalton

________ had no direct evidence for the existence of atoms but based his conclusions on chemical observations.

Structural formulas

________: show the order in which atoms are bonded.

Perspective drawings

________: show the three- dimensional array of atoms in a compound.

Robert Millikan

________ determined the charge on the electron in 1909:

J.J.Thomson

________: credited with discovery of the electron.

ions

When atoms lose or gain electrons, they become ________.

nucleus

The ________ is a tiny region that contains virtually all the mass of the atom.

Anions

________: negative and are formed by elements on the right side of the periodic chart.

Thomson

________ calculated the charge /mass ratio of the cathode ray particles to be 1.76 x 10^8 coulombs /gram (C /g)

electrons

Rapidly moving ________ occupy most of the volume of the atom.

Ernest Rutherford

________: basic structure of the atom; existence of the nucleus.

visible beam

A(n) ________, the "cathode ray "appeared when high voltage applied across the electrodes and was deflected by an applied magnetic field.

Non metals

________ tend to gain electrons to form anions.

Molecular formulas

________: give the exact number of atoms of each element in a compound.

proton

The ________, neutron and electron are the subatomic particles that affect chemical behavior.

Empirical formulas

________: give the lowest whole- number ratio of atoms of each element in a compound.

Compounds

________ are formed when atoms of more than one element combine; a given ________ always has the same relative number and kind of atoms.

Metals

________ tend to lose electrons to form cations.

Thomson

________ measured the deflection of the ray at any particular magnetic field strength.

Robert Millikan

________: the charge on the electron.

J.J.Thomson

credited with discovery of the electron

Robert Millikan

the charge on the electron

Ernest Rutherford

basic structure of the atom; existence of the nucleus

Marie Curie

radioactivity

Structural formulas

show the order in which atoms are bonded

Perspective drawings

show the three-dimensional array of atoms in a compound

Empirical formulas

give the lowest whole-number ratio of atoms of each element in a compound

Molecular formulas

give the exact number of atoms of each element in a compound

Cations

positive and are formed by elements on the left side of the periodic chart

Anions

negative and are formed by elements on the right side of the periodic chart

Dalton's postulates

Each element is composed of atoms

All atoms of a given element are identical, but the atoms of one element are different from the atoms of all other elements

Atoms of one element can’t be changed into atoms of a different element by chemical reactions; atoms are neither created nor destroyed in chemical reactions

Compounds are formed when atoms of more than one element combine; a given compound always has the same relative number and kind of atoms