Module 13

Question 1

Model:

Answer 1

A schematic description of a system that accounts for its known properties.

Question 2

Nucleus:

Answer 2

the center of an atom, containing the protons and neutrons.

Question 3

Atomic number:

Answer 3

the number of protons in an atom.

Question 4

Mass number:

Answer 4

the sum of the numbers of neutrons and protons in the nucleus of an atom.

Question 5

Isotopes:

Answer 5

Atoms with the same number of protons but different numbers of neutrons.

Question 6

Element;

Answer 6

A collection of atoms that all have the same number of protons.

Question 7

Radioactive isotope:

Answer 7

An atom with a nucleus that is not stable

Question 8

Half-life:

Answer 8

the time it takes for half of the original sample of radioactive isotope to decay.

Question 9

Order the 3 parts of the atom in terms of their mass, from least massive to most massive.

Answer 9

electron, proton, neutron.

Question 10

What force keeps the protons and neutrons in the nucleus? What causes the force?`

Answer 10

the nucleus force the exchange of pions between protons and/or neutrons

Question 11

what force keeps the electrons orbiting around the nucleus

Answer 11

electromagnetic force.

Question 12

what are atoms mostly made of?

Answer 12

empty space.

Question 13

An atom has an atomic number of 34. How many protons and electrons does it have? What is it’s Symbol?

Answer 13

34 protons 34 electrons Se

Question 14

List the number of protons, electrons, and Neutrons for each of the following atoms.
A Neon-20 (Ne)  
B Fe- 56
C La 139
d Mg 24

Answer 14

A. 10 protons 10 electrons 10 neutrons.
B. 26 protons 26 electrons 30 neutrons.
C. 57 protons 57 electrons 82 neutrons
D. 12 protons 12 electrons 12 neutrons.

Question 15

2 atoms are istopes. The first has 18 protons and 20 neutrons. the second has 22 neutrons. How many protons does the second atom have?

Answer 15

18 protons

Question 16

Circle and of the following atoms that are isotopes

Cd-112 Sn-112 Xe-120 Sn-124 Ar-40 Sn-120

Answer 16

Sn-112 Sn-124 Sn-120

Question 17

How many electrons can fit on the first Bohr Orbit? The Second Bohr Orbit? The Third Bohr Orbit? The Forth Bohr Orbit? The Fifth Bohr Orbit?

Answer 17

1-2 2-8 3-18 4-32 5-50

Question 18

Draw what the bohr modle says a Mg-25 atom would look like.

Answer 18

the table of elements says that the element has 12 protons 12 electrons and a 24.3 atomic number 12- 25 so there are 13 neutrons draw 12 protons and 13 neutrons in the nucleus 2 electrons 8 electrons then 2 electrons.

Question 19

What is the largest Bohr orbit in a U atom and how many electrons are in it? (92)

Answer 19

5, 32

Question 20

Why is the strong nuclear force such a short range force?

Answer 20

Because the nuclear force is the exchange of pions and pions have a very short life time so they can only be exchanged at a close range.

Question 21

Determine the daughter products produced in the beta decay of the 2 radioactive isotopes shown below.
a Tc 98 b I 125

Answer 21

a how to do it is… find the symbol and notice the protons then find the difference between the protons and the atomic number 98 then minus one from the neutrons and add one to the protons`

Question 22

Determine the daughter products produced in the Alpha decay of the 2 radioactive isotopes shown below:
A. Bi 212 b. I 125

Answer 22

a how to do it is… find the symbol and notice the protons then find the difference between the protons and the atomic number 212 then minus 2 from each then find the new symbol.`

Question 23

a radioactive isotope goes trough radioactive decay but the isotope’s number of protons and neutrons does not change. What kind of radioactive decay occurred?

Answer 23

gamma decay

Question 24

the half-life of the radioactive decay of 226Ra is 1,600 yr. If a sample of 226Ra Originally had a mass of 10 grams, how many grams of 226Ra would be left after 3,200 years?

Answer 24

10 -5 - 2.5

Question 25

the half-life of the man-made isotope 11C is 20 minutes. If a scientists makes 1 gram of 11C, how much will be left in one hour?

Answer 25

(3 half-lifes)

1-0.5-0.25-0.125

Question 26

Why is radioactive dating unreliable in most situations?

Answer 26

Because assumptions must be made as to the original condition of the object. These assumptions are usually filled with errors.

Question 27

List the 3 types of radioactive particles in the order of their ability to travel through matter. Start with the one which cannot pass through much

Answer 27

Alpha particle, beta particle, gamma ray