Ap Chem. Ch.2

Question 0

What are the 4 postulates of the atomic theory?

Answer 0

1. elements are composed of Atoms
2. All atoms of an element are identical, different from other elements (first part not true!)
3. In chemical reactions Atoms are not changed into different types of Atoms. Atoms are neither created nor destroyed.
4. Compounds are formed when Atoms of all elements combine

Question 1

Scientist to propose the atomic theory

Answer 1

Dalton

Question 2

Law that states the relative kinds and numbers of atoms are constant for a given compound.

Answer 2

Law of constant composition

Question 3

During a chemical reaction, the total mass before reaction is equal to the total mass after reaction.

Answer 3

Law of conservation of mass

Question 4

Law that states if two elements A and B combine to form more than one compound, then the mass of B which combines with the mass of A is a ratio of small whole numbers

Answer 4

Law of multiple proportions

Question 5

Scientist that was credited with discovering the electron in the cathode ray experiments.

Answer 5

J.J.Thompson

Question 6

Oil-drop experiment and the mass of an electron.

Answer 6

Millikan

Question 7

Becquerel and radioactivity

Answer 7

Some substances spontaneously emit high energy Rays.

Question 8

Rutherford

Answer 8

Radiation experiments

Question 9

Chadwick

Answer 9

Discovered the neutron

Question 10

Isotopes

Answer 10

Differ in the number of neutrons

Question 11

Atomic number

Answer 11

Number of protons in the nucleus.

Question 12

Mass number

Answer 12

Total number of nucleons in the nucleus.(protons and neutrons)