Ch 4: Atomic Theory & Atomic Structure

Question 1

What did Democritus think about atoms?

Answer 1

Indivisible, indestructible, and made up matter.

Question 2

What did Dalton do to Democritus’ ideas?

Answer 2

Transformed the ideas into a scientific theory.

Question 3

What three laws led to Dalton’s atomic theory?

Answer 3

1. Law of Definite Proportion
2. Law of Conservation of Mass
3. Law of Multiple Proportions

Question 4

Dalton’s atomic theory: all ______ is made up of _____; atoms are ______________.

Answer 4

matter
atoms
indestructible

Question 5

Dalton’s atomic theory: all atoms of a particular _______ are _________ to each other and _________ from atoms of other elements.

Answer 5

element
identical
different

Question 6

Dalton’s atomic theory: atoms are rearranged in a ________ reaction.

Answer 6

chemical

Question 7

Dalton’s atomic theory: _________ are formed when two or more _________ kinds of atoms join together.

Answer 7

compounds

different

Question 8

How are atoms observed?

Answer 8

Using instruments such as scanning tunneling microscopes.

Question 9

What are the three types of subatomic particles?

Answer 9

Electrons, protons, and neutrons.

Question 10

Who discovered elections using cathode ray tube experiments?

Answer 10

JJ Thomson

Question 11

Whose experiments were to find the quantity of charge carried by an electron?

Answer 11

Robert A. Millikan

Question 12

Who discovered protons?

Answer 12

Eugen Goldstein

Question 13

Who confirmed the existence of neutrons?

Answer 13

James Chadwick

Question 14

What experiment tested to see whether protons/elections were arranged or randomized?

Answer 14

Rutherford’s Gold-Foil Experiment

Question 15

The Rutherford atomic model: the atom is mostly _____. Most of the ____ is in a very small region at the center.

Answer 15

empty

mass

Question 16

The Rutherford atomic model: the protons and neutrons are located at the _______.

Answer 16

nucleus

Question 17

The Rutherford atomic model: the electrons are distributed ______ the nucleus and occupy almost all the ______ of the atom.

Answer 17

around

volume

Question 18

Elements are different because they contain different numbers of _______.

Answer 18

protons

Question 19

The number of neutrons in an atom is the difference between the ____ ______ and ______ ______.

Answer 19

mass number

atomic number

Question 20

Because isotopes of an element have different numbers of neutrons, they also have different ____ _______.

Answer 20

mass numbers

Question 21

How does one calculate the atomic mass of a number?

Answer 21

Multiply the mass of each isotope by its natural abundance, expressed as a decimal, and then add the products.

Question 22

To calculate the atomic mass of a number, what do you need to know?

Answer 22

The number of stable isotopes of the element, the mass of each isotope, and the natural percent abundance of each isotope.

Question 23

What does the Periodic Table allow you to do?

Answer 23

Easily compare the properties of one element (or a group of elements) to another element (or groups of elements).