chapter 3

Question 1

the basic principles of the atomic theory that are still recognized today were first conceived by

Answer 1

Dalton

Question 2

atoms of the same element can differ in

Answer 2

mass number

Question 3

the nucleus of the atom was discovered as a result of experimentation by

Answer 3

rutherford

Question 4

the number of protons in an element is called its

Answer 4

atomic number

Question 5

atoms of one element that have different masses are called

Answer 5

isotopes

Question 6

negatively charged subatomic particles are called

Answer 6

electrons

Question 7

the isotope of hydrogen that has 2 neutrons is

Answer 7

tritium

Question 8

positively charged subatomic particles are called

Answer 8

protons

Question 9

the total number of protons and neutrons in the nucleus of an isotope is called its

Answer 9

mass number

Question 10

the idea that electrons are in atoms was discovered by

Answer 10

thompson

Question 11

the idea that electrons had a negative charge was discovered by

Answer 11

milliken

Question 12

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

Answer 12

law of conservation of mass

Question 13

chemical compound contains the same elements in exactly the same proportions by mass regardless of the size of the sample or source of the compound

Answer 13

law of definite proportion

Question 14

if two or more different compounds are composed of the same two elements, then 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 number

Answer 14

law of multiple proportions