P5.1 - The Nucleus Flashcards
What is in the nucleus? [2]
- protons
- neutrons
Why is the nucelus significant? [1]
most of the mass of an atom is concentrated here
What are protons? [3]
- positively charged particles
- relative charge of +1
- relative mass of 1
What are neutrons? [3]
- neutral particles
- no charge (0)
- relative mass of 1
How do you find out the atomic number of an atom? [1]
the number of protons
How do you find out the atomic mass of an atom? [1]
the total number of protons and neutrons
What are electrons? [3]
- spin around the nucleus in the outermost shell
- relative charge of -1
- relative mass of 1/2000
What is a nucleon number? [1]
the mass number or the atomic mass
What is the nuclide notation? [1]
ᴬ
X
ᶻ
What do the letters in nuclide notation represent? [3]
- A = mass number
- Z = atomic number
- X = element
What is an isotope? [2]
atoms of the same element with the same number of protons but different numbers of neutrons
What do isotopes have in common and different? [2]
- common: same chemical properties
- different: physical properties
What does it mean if an isotope is radioactive? [2]
- their nuclei are unstable and break down over time
- this emits radiation in the form of alpha particles, beta particles or gamma rays
What is an example of different isotopes? [2]
- Carbon-12 = stable, 6p and 6n
- Carbon-14 = radioactive, 6p and 8n
What is the relationship between the proton number and the relative charge on a nucleus? [2]
- realtive charge of a nucleus is determined by the number of protons as neutrons don’t contribute to the charge
- neutrons only contribute to the mass of the nucleus
What is an example of the relationship between the proton number and the relative charge on a nucleus? [1]
e.g. Helium atom has 2 protons = relative charge of its nucleus is +2
What is nuclear fission? [2]
the process where a large, unstable nucleus splits into two smaller nuclei, releasing energy
How does nuclear fission work? [3]
- a tiny particle called a neutron hits a big atom, a large nucleus
- the large nucleus breaks into two smaller pieces and releases a lot of energy
- more tiny neutrons fly out and can hit other atoms making a chain reaction
What is nuclear fusion? [2]
the process where two small nuclei join together to form a large nucleus, releasing energy
How does nuclear fusion work? [3]
- occurs in extremely hot temperatures and pressures like the sun
- nuclei smash together really hard and stick together to make a bigger atom
- the resulting nucleus is larger and gives of a lot of energy
What is radiation? [2]
- the transfer of energy in the form of electromagnetic waves or particles
- without the need of a medium to travel through
