chemistry chapter 4

1

100

which of the following was a belief that matter was made of separate, discrete particles?

the continuous theory of matter 

200

J.J. Thomson concluded that every atom contained small, ___________ particles. 

negatively charged

300

In atomic notation, Z represents the number of _________ in an atom.

protons

400

The smallest particle capable of chemical interactions is the ______________.

atom

500

Atoms with the same atomic number but different mass numbers are called ________________

isotopes

2

100

who was the first to refer to matter as being made of discrete particles? 

Democritus 

200

Who formulated a new atomic model because of discoveries made during an alpha particle experiment?

Ernest Rutherford

300

Two different isotopes of a single element would have the same number of __________ but a different number of _________.

protons; neutrons 

400

Every compound is formed of elements combined in specific rations by mass that are unique for that compound according to ___________

the law o definite proportion

500

To determine the number of neutrons for a given isotope, subtract the atomic number from the ____________

mass number

3

100

which of the following refers to a relationship in which masses of elements can combine to form a particular ratio that can be reduced to small, whole numbers?

the law of multiple proportions

200

The experiment in which alpha particles were deflected by gold foil was conducted by __________ 

Ernest Rutherford 

300

The sum of the number of neutrons and the number of protons in an isotope represents the __________ of the isotopes.

mass number

400

Dalton created a table of ________________ to assign relative masses to atoms.

elements

500

Weighted averages of isotopes of an element determine its ___________

atomic mass

4

100

The fact that any sample of water contains 8 g of oxygen for every 1 g of hydrogen illustrates _______________

the law of definite proportion

200

Who is credited with the discovery of the neutron?

James Chadwick

300

Tritium is an isotope of hydrogen that has a mass number of 3. WHat is its isotopic notation? 

3  H

1

400

Negatively charged particles in atoms are called _____________

electrons

500

When determining atomic mass, more common isotopes are given _____________ weight than other isotopes.

more

5

100

J.J. Thompson's cathode rays were composed of ____________

electrons

200

Changes were made to Rutherford's atomic model to include the addition of ____________

neutrons

300

The weighted averages of the isotopes of an element determine its ___________.

atomic mass

400

Rutherford's model showed that the ___________ of an atom is a small region in its center that is positively charged. 

nucleus

500

One-twelfth the mass of carbon-12 is defined as a(n) __________________

atomic mass unit