AQA A GCE Physics - Particles and Radiation

What are the 4 steps of the scientific process?

-Question – make an observation

-Answer, by forming theory or model

-Prediction/Hypothesis

-Test

 

Where do scientists publish their work?

-Scientific journals

 

What do scientific journals contain?

-Scientific reports

 

How are scientific journals judged before they are published?

-Peer review

 

How can scientists make sure scientific journals are of good standard?

-If the experiments can be reproduced

 

What does testing a theory entail?

-Repeating exact experiments

-Using theory to make new predictions, and then testing them with new experiments

 

Which 3 factors can influence the decision about science?

-Economic factors

-Social factors

-Environmental factors

 

What is the generic term for protons and neutrons?

-Nucleons

 

What is the charge and relative mass of a proton?

-+1 and 1

 

What is the charge and relative mass of a neutron?

-0 and 1

 

What is the charge and relative mass of an electron?

--1 and 1/2000

 

How big is each atom ≈ in diameter?

-1 × 10^-10 m (0.1 nanometres)

 

How big is the nucleus compared to the atom?

-10,000 times smaller

 

What is most of the atom made of?

-Empty space

 

What defines an element?

-Proton number

 

What is another name for the proton number?

-Atomic Number (Z)

 

In a ******* atom, the number of electrons equals the number of protons.

-Neutral

 

What do the number of electrons cause in an atom?

-Reactions and chemical behaviour

 

What is the symbol for nucleon number?

-A

 

What is the nucleon number basically the same as? Why?

-Atomic mass

-Electron mass is negligible

 

What is the name given to the visual representation of sub atomic particles in an atom and nucleus?

-Nuclear model

 

What is an isotope?

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

 

What are the 2 other isotopes of hydrogen?

-Deuterium and Tritium

 

How many neutrons does the normal hydrogen have?

-0

 

How many neutrons does deuterium have?

-1

 

How many neutrons does tritium have?

-2

 

Why is hydrogen not changing as an atom, when neutrons are added?

-Changing number of neutrons does not affect the atom’s chemical properties.

 

How does the neutron number affect the atom?

-Affects the stability of the nucleus.

 

In general the greater the number of neutrons compared with the number of protons, the more u******* the nucleus.

-Unstable

 

What is the name given to most unstable nuclei? What do they do to become stable?

-Radioactive

-Decay

 

The s***** nuclear force binds n******* together.

-Strong

-Nucleons

 

Which two other forces act on nucleons in the nucleus?

-Electrostatic forces

-Gravitational forces

 

What would happen if these (above) were the only forces acting in the nucleus?

-Nucleons would fly apart

 

Why would the nucleons fly apart despite gravity acting towards the centre?

-Gravitational force is so small, you can just ignore it

 

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