C16 Terms

Question 1

law of definite proportions

Answer 1

Established that masses if chemical substances combine in definite repeatable ratios

Question 2

core-envelope model

Answer 2

Based on the caloric theory

Question 3

plum-pudding model

Answer 3

Atoms are masses that have a positively charged (pudding) in which the negatively charged electrons stay

Question 4

nuclear model

Answer 4

Every atom has a nucleus and electrons circle around it

Question 5

planetary model

Answer 5

Electrons circle around the nucleus

Question 6

quantum model

Answer 6

Electrons move in waves around the nucleus

Question 7

orbital

Answer 7

Subregions of space

Question 8

nucleon

Answer 8

Neutrons and protons in the nucleus

Question 9

elementary particle

Answer 9

Subatomic particles that are the building blocks of photons neutrons and electrons

Question 10

atomic number (Z)

Answer 10

The number of protons in the nucleus

Question 11

isotope

Answer 11

Aims of elements that have different numbers of neutrons

Question 12

mass number

Answer 12

Tells isotopes apart

Question 13

isotopic notation

Answer 13

Shows both the atomic and mass numbers of the element

Question 14

atomic mass

Answer 14

The mass of an electron expressed in atomic mass units

Question 15

atomic mass unit (u)

Answer 15

The mass equal to 1/12th the mad of a carbon atom

Question 16

energy level

Answer 16

Represent the regions where an electron with a certain amount of energy is most likely to be found.

Question 17

electron configuration

Answer 17

Is the arrangement of the energy levels and the positions that electrons can take within those energy levels for a given number of electrons.

Question 18

valence electron

Answer 18

The electrons in the outermost energy level

Question 19

nuclear chemistry

Answer 19

The study of changes in atomic nuclei

Question 20

radioactivity

Answer 20

The emission of nuclear radiation

Question 21

nuclear radiation

Answer 21

The rays and particles emitted by unstable nuclei

Question 22

alpha particle

Answer 22

Positively charged particles

Question 23

beta particle

Answer 23

Negatively charged particles

Question 24

gamma decay

Answer 24

A nucleus shedding energy by releasing gamma rays

Question 25

alpha decay

Answer 25

The atoms nucleus loses two protons and two neutrons

Question 26

beta decay

Answer 26

The atom loses a beta particle and emits gamma rays

Question 27

radioactive dating technique

Answer 27

Using nuclear decay to date things

Question 28

nuclear bombardment reaction

Answer 28

When a nucleus is stuck by a high energy particle

Question 29

nuclear fission

Answer 29

The splitting of an atom

Question 30

chain reaction

Answer 30

When one atom after another is broken apart

Question 31

nuclear fusion

Answer 31

The crushing of two atoms to form a larger atom

Question 32

What is the most important aspect of a scientific model?

Answer 32

It has to work

Question 33

Discuss one aspect of John Dalton’s atomic model that was set aside by a later discovery.

Answer 33

The core envelope model was based on the caloric theory

Question 34

What was the most significant question about the atom after Thomson’s discovery of the electron?

Answer 34

The extra mass that was measured

Question 35

What phenomenon did Niels Bohr observe that convinced him that every atom has a unique electron structure?

Answer 35

How light was refracted

Question 36

How do orbitals in the quantum model of the atom differ from orbits in the planetary model?

Answer 36

There exact position can’t be found

Question 37

What is the most important use of an elements atomic number? What else an we know from a neutral atoms atomic number?

Answer 37

To tell elements apart. The number of electrons

Question 38

How do atoms of the same element differ?

Answer 38

In the number of electrons

Question 39

Explain the difference between an atoms mass number and atomic mass. Why are both needed in chemistry?

Answer 39

Mass number is the mass of the whole atom and atomic mass is the added mass of all the particles in the atom. Mass number and atomic mass can differ.

Question 40

What arrangement of electrons is usually the most stable for an atom?

Answer 40

When there is 8 electrons in the outermost sphere.

Question 41

(True or false) The element oxygen has eight valence electrons.

Answer 41

True

Question 42

What makes an element radioactive? Which elements found in nature have mainly radioactive isotopes?

Answer 42

When the nuclei is unstable. Polonium though uranium.

Question 43

What kinds of changes to a nucleus occur for each kind of nuclear decay?

Answer 43

For gamma decay there is no change except the nuclei loses energy. For alpha decay two protons and two neutrons are lost. For beta decay a beta particle is lost.

Question 44

What is the source of energy released in fission and fusion reactions?

Answer 44

The nucleus.

Question 45

What are the two most difficult aspects of producing fusion energy for electrical generation?

Answer 45

Making a container to hold the particles in and heating the particles to the right temperature.