Radioactivity and stuff

Question 1

Meaning of “atomos”

Answer 1

indivisible

Question 2

The idea of atoms was conceived by ___ and ___.

Answer 2

Leucippus and Democritus.

Question 3

He thought that the world was composed of air, earth, fire, and water.

Answer 3

Empedocles

Question 4

Created the atomic theory.

Answer 4

John Dalton

Question 5

negatively charged particles

Answer 5

electrons

Question 6

Measured the charge of electrons with his oil drop experiment

Answer 6

Robert Millikan

Question 7

He discovered that highly energetic rays could penetrate matter.

Answer 7

Wilhelm Roentgen

Question 8

He associated X_rays with fluorescent materials.

Answer 8

Henri Becquerel.

Question 9

Any material that spontaneously emits radiation is said to be ___.

Answer 9

radioactive

Question 10

Particles with a positive charge of +2.

Answer 10

Alpha rays

Question 11

Negatively charged electrons which are attracted to positively charged plates.

Answer 11

Beta rays

Question 12

Electromagnetic radiation of extremely high penetrating power.

Answer 12

Gamma rays

Question 13

Ernest Rutherford’s 21-year old student.

Answer 13

Ernest Marsden

Question 14

Rutherford’s assistant who used alpha particles to probe the atom.

Answer 14

Hans Geiger

Question 15

Positively charged parts of the atom

Answer 15

Protons

Question 16

A small region at the center of the atom.

Answer 16

Nucleus

Question 17

One of Rutherford’s students

showed that each uncharged particle emitted by radioactive atoms has a mass approx. equal to a proton.

Answer 17

James Chadwick

Question 18

neutral charged particles

Answer 18

Neutrons

Question 19

Atoms of the same element that have different number of neutrons.

Answer 19

Isotopes

Question 20

Number of protons is equal to___.

Answer 20

Atomic number

Question 21

p+n

Answer 21

Atomic mass