Chapter 3

Question 1

Law of conservation of mass

Answer 1

Mass is neither created nor destroyed during ordinary chemical reactions or physical changes

Question 2

law of definite proportion

Answer 2

Every chemical compound contains fixed and constant proportions

Question 3

Law of multiple proportions

Answer 3

If two or more different compounds are composed of the same two elements in the ratio of the masses of the second element combined with a certain mass of the first element is always a ratio of small whole numbers

Question 4

Dating five statements

Answer 4

• All matter is made of atoms
• All atoms of a given element are identical a mass and properties(proven wrong)
• Compounds are formed by a combination of two or more different kinds of atoms
• A chemical reaction is a rearrangement of atoms
• Atoms are indivisible and indestructible(proven wrong)

Question 5

Isotopes

Answer 5

Have equal number of protons but different number of neutrons

Question 6

Dalton

Answer 6

(Pool ball)
Dalton’s model
Found the atom

Question 7

Millikan

Answer 7

Found that The mass of an electron is at least 1000 times smaller than the lightest atom
Oil drop experiment

Question 8

Thomson

Answer 8

Plum pudding model

Discovered the electron by experimenting with a cathode ray tube

Question 9

Rutherford

Answer 9

Nuclear model
Discovered the nucleus
Gold foil using alpha particles experiment