The nuclear model of the atom

Question 1

Describe the structure of an atom.

Answer 1

a positively charged nucleus and negatively charged electrons in orbit around the nucleus

Question 2

How can atoms form positive ions?

Answer 2

losing electrons

Question 3

How can atoms form negative ions?

Answer 3

gaining electrons

Question 4

What is an experiment to support the nuclear model of the atom?

Answer 4

scattering of alpha particles by a sheet of thin metal

Question 5

What does Rutherford’s Alpha Particle Scattering experiment prove?

Answer 5

• there is a very small nucleus surrounded by mostly empty space
• nucleus contains most of atom’s mass
• positive nucleus

Question 6

What is the nucleus composed of?

Answer 6

protons and neutrons

Question 7

Relative charge of proton?

Answer 7

+1

Question 8

Relative charge of neutron?

Answer 8

0

Question 9

Relative charge of electron?

Answer 9

-1

Question 10

What is the proton number?

Answer 10

number of protons found in the nucleus

Question 11

What is the atomic number?

Answer 11

number of protons found in the nucleus

Question 12

The electron and proton numbers are equal in…

Answer 12

an atom (neutral)

Question 13

The electron and proton numbers are unequal in…

Answer 13

ions (charged)

Question 14

What is the nucleon number?

Answer 14

total number of protons and neutrons in the nucleus

Question 15

What is the mass number?

Answer 15

total number of protons and neutrons in the nucleus

Question 16

How can you calculate the number of neutrons in a nucleus?

Answer 16

nucleon number - proton number

Question 17

What is the symbol A?

Answer 17

nucleon number

Question 18

What is the symbol Z?

Answer 18

proton number

Question 19

What is the symbol X?

Answer 19

element

Question 20

What is the symbol for an element?

Answer 20

X

Question 21

What is the symbol for nucleon number?

Answer 21

A

Question 22

What is the symbol for proton number?

Answer 22

Z

Question 23

What is an isotope?

Answer 23

atoms of the same element with the same number of protons and electrons, but different neutron numbers

Question 24

What is an isotope, in terms of nucleon and proton numbers?

Answer 24

different nucleon number of the atoms, same proton number

Question 25

Describe the process of nuclear fusion.

Answer 25

lighter nuclei collide with high energy and join to form a larger nucleus, releasing energy

Question 26

What is the difference between nuclear fission and fusion?

Answer 26

nuclear fission - splitting of heavy nuclei
nuclear fusion - joining of 2 light nuclei

Question 27

What is the nuclide equation for nuclear fusion?

Answer 27

• you add the nucleon and proton numbers
• total nucleon number is the same before and after

Question 28

Describe the process of nuclear fission.

Answer 28

• heavy nuclei are often unstable, so they break apart
• either independently or if a neutron is fired into the large nucleus, triggering it to break apart
• energy is released

Question 29

What is the nuclide equation for nuclear fusion?

Answer 29

• total nucleon number is conserved
  atom + neutron -> atom1 + atom2 + neutrons

Question 30

Describe the mass and energy changes in nuclear fission and fusion.

Answer 30

they both release energy by decreasing mass slightly

Question 31

How is energy released in nuclear fission/fusion?

Answer 31

decreasing mass slightly, typically around 0.1%