Unit 2: Atomic Theory

Question 0

Ernest Rutherford

Answer 0

Mass and positive charge of an atom exists in the nucleus

Question 1

J.J Thompson

Answer 1

• *Atoms have subatomic Particles
• *Subatomic particles have a charge
• *Isotopes

Question 2

Subatomic Particles are….

Answer 2

Protons, Neutrons and Electrons

Question 3

Electrons

Answer 3

• *Negative charge
• *Almost no mass: 1/2000
• *Account for the VOLUME of an atom

Question 4

Protons

Answer 4

• *Positively Charged
• *Neutralizes the electron (negative)
• *Has mass (1 amu)
• *Located in Nucleus

Question 5

Neutrons

Answer 5

• *Neutral Charge
• *Located in Nucleus
• *Has mass (1amu)

Question 6

Atomic Number

Answer 6

The amount of PROTONS an ELECTRONS in an atoms nucleus and determines the IDENTITY of that atom

Question 7

Atomic Mass

Answer 7

Number of PROTONS and NEUTRONS that an atom has

Question 8

Isotopes

Answer 8

Elements that have different mass (neutrons) numbers but are the same identities/atomic number

Question 9

Average Atomic Mass (amu)

Answer 9

Weighted average mass of all the naturally occurring isotopes of that specific element.

Question 10

Nuclear Chemistry

Answer 10

Study of the structure of atomic nuclei and the change they undergo

Question 11

Marie Curie

Answer 11

Named the process b which certain atoms gives off radioactive rays and called it radiation

Question 12

Radiation

Answer 12

The rays and particles emitted by a radioactive source

Question 13

Radioisotopes

Answer 13

Isotopes with unstable nuclei (more neutrons then protons).

Question 14

Radioactive Decay

Answer 14

When unstable nuclei emit radiation to get a more stable nuclei. During decay, atoms lose energy through 3 types of radiation

Question 15

Alpha (a)

Answer 15

• *Same composition of Helium nucleus (2 protons, 2 neutrons, mass of 4)
• *CHARGE: 2+
• *SPEED: Slow Moving and not very penetrating

Question 16

Beta (B)

Answer 16

A very fast moving electron that has been from a neutron of an unstable nucleus

• *Charge: -1 negative
• *SPEED: greater penetrating power because they are lightweight and fast

Question 17

Gamma Rays (Y)

Answer 17

High energy short wavelength electromagnetic radiation

• *CHARGE: no charge or mass
• *Always accompanies alpha or beta radiation and accounts for the energy loss

Question 18

Half-Life

Answer 18

Unit of measurement that measures the radioactive decay rates.

Question 19

Nuclear Fission

Answer 19

The division of an atoms nucleus in order to attain stability in the nucleus
Releases a LARGE amount of energy and several neutrons.

Question 20

Nuclear Fusion/Thermonuclear Reactions

Answer 20

The combination of different atomic nuclei in order to attain stability.
Requires VERY LARGE amounts of energy to actually happen

Question 21

Critical Mass

Answer 21

In Nuclear Fission, if you have enough mass to start with, then a chain reaction can occur and create a long reaction of nuclear fission.

Question 22

Democritus (400 B.C)

Answer 22

Greek philosopher who fort came up with the idea of an Atom.

Question 23

John Dalton (1893)

Answer 23

English Schoolteacher, proposed atomic theory of matter.

Question 24

Atomic Theory of Atom (Dalton)

Answer 24

1. All matter is made up of atoms 2. Atoms of the same element are identical 3. Atoms of different elements combine in whole number ratios to form compounds 4. Chemical reactions only involve the Rearrangement of atoms 5. No atoms are created or destroyed

Question 25

Law of Conservation of Mass

Answer 25

Mass is neither destroyed or created, just rearranged, in a chemical reaction

Question 26

Law of Definite Proportions

Answer 26

Chemical Compounds with the same elements are always the same proportion, no matter the size or mass

Question 27

Law of Multiple Proportions

Answer 27

If two or more compounds are complied of the same two elements then the ratio of the first and second elements combined is a ratio of small numbers