IScience - Chapter 9 Test

Question 1

Thomson’s experiments led to the discovery of the ___.

Answer 1

Electron

Question 2

For an atom to be neutral, the number of protons must equal the number of ___.

Answer 2

Electrons

Question 3

The idea of the atom was first proposed by ___.

Answer 3

Democritus

Question 4

An element can be identified by the number of ___ in its nucleus.

Answer 4

Protons

Question 5

The mass of an ___ is about equal to the mass of a proton.

Answer 5

Neutron

Question 6

___ used the cathode ray experiments and determined that cathode rays are negatively charged.

Answer 6

Thomson

Question 7

___ was invented in 1981 and allowed scientists to first see individual atoms.

Answer 7

Scanning tunneling microscope (STM)

Question 8

The 3 basic components of an atom are ___.

Answer 8

Protons, neutrons, and electrons

Question 9

The nucleus of an atom consists of ___.

Answer 9

Protons and neutrons

Question 10

A single proton has what electrical charge?

Answer 10

Positive

Question 11

What two particles would be attracted to each other?

Answer 11

Electrons and protons

Question 12

In ___, the atomic number decreases by two.

Answer 12

Alpha decay

Question 13

In ___, the atomic number increases by one.

Answer 13

Beta decay

Question 14

A certain atom has 26 protons, 26 electrons, and 30 neutrons. Its atomic mass is ___.

Answer 14

56

Question 15

The energy levels of an atom are occupied by ___.

Answer 15

Electrons

Question 16

___ believed that all matter was made of fire, water, air, and earth.

Answer 16

Aristotle

Question 17

___ discovered neutrons.

Answer 17

Chadwick

Question 18

___ first called the building blocks of matter atomos.

Answer 18

Democritus

Question 19

___ first introduced the concept that atoms combine in specific ratios.

Answer 19

Dalton

Question 20

___ proposed a circular path for electrons.

Answer 20

Bohr

Question 21

___ used the Gold Foil Experiment to observe alpha particles.

Answer 21

Rutherford

Question 22

___ discovered electrons.

Answer 22

Thomson

Question 23

___ is the name of the modern atomic model.

Answer 23

Electron cloud model

Question 24

___ discovered radiation in uranium.

Answer 24

Curie

Question 25

Thomson’s discoveries came about by using this.

Answer 25

Cathode ray tube

Question 26

Describe the difference between an isotope, an ion, and an element that undergoes radiation.

Answer 26

Isotope = different # of neutrons
Ion = different # of electrons 
Radiation = different # of protons