Chapter 1 Flashcards
What does an atom consist of?
Central positively charged nucleus containing protons and neutrons (nucleons)
What is the diameter of an atom? (Atomic diameter)
10^-10m
What surrounds the nucleus of an atom?
Electrons
What is the diameter of the nucleus of an atom?
10^-15m or 1 femtometer
What is the charge and relative charge of a proton?
1.6 x10^-19, +1
What is the charge and relative charge of a neutron?
0, 0
What is the charge and relative charge of a electron?
-1.6 x10^-19, -1
What is the symbol for proton/atomic number?
Z
What is the proton number equal to?
Number of protons in the nucleus of an atom
What is the symbol for mass/nucleon number?
A
What is the mass number equal to?
Number of protons + number of neutrons in the nucleus of an atom
What are isotopes?
Atoms with the same amount of protons and different numbers of neutrons
If 2 different atoms have the same proton number, they are of…?
The same element
Are all isotopes radioactive?
No
What are radioactive isotopes called?
Radioisotopes
What is the equation of specific charge?
charge of particle / mass of particle
Which out of protons, neutrons and electrons have the largest specific charge?
Electrons
Define the strong nuclear force
Stable isotopes have nuclei that don’t disintegrate. There must be a force holding them together
What does the strong nuclear force overcome in the nucleus?
Electrostatic force of repulsion between protons in the nucleus
What does the strong nuclear force do?
Keep protons and neutrons together
What is the range of the strong nuclear force?
3-4 femtometers (diameter of nucleus)
What is the range of electrostatic force? And when does the range start to decrease?
Infinite. Starts to decrease when the range between 2 charged particles increases
What distance does the strong nuclear force start to act as a repulsive force?
When distance is less than 0.5 femtometer
Why does the strong nuclear force turn into a repulsive force at very small distances?
To prevent protons and neutrons being pushed into each other. This prevents the nucleus collapsing intoa point
When is electromagnetic radiation emitted?
When charged particles lose energy
Give 2 examples when electromagnetic radiation would be emitted
- Electrons decreasing in energy inside an atom (light)
2. Electrons losing energy when stopped by a solid material (X-rays)
Name the electromagnetic spectrum in order of decreasing wavelengths/increasing frequency
Radio, microwave, infrared, visible, ultra violet, x-ray, gamma ray
What is the wavelength of a radio wave?
Greater than 0.1m
What is the wavelength of an microwave?
0.1mm-1mm
What is the wavelength of an infrared wave?
1mm to 700nm
What is the wavelength of visible light?
700nm to 400nm
What is the wavelength of an ultraviolet wave
400nm to 1nm
What is the wavelength of an x-ray?
less than 1nm
What is the wavelength of a gamma ray?
less than 1nm
Do all forms of radiation travel at the same speed through a vacuum?
Yes
What speed to all forms of radiation travel at in a vacuum?
3 x10^8m/s
What is a photon?
A packet of wave energy
How is EM radiation emitted?
As a short burst of waves in all directions
What does a photon contain?
A set amount of energy
Define antimatter
All particles of normal matter have a corresponding particle that:
- Has the same mass as the normal particle
- Has opposite charge (if normal particle is charged)
- Will undergo annihilation with normal particle if they meet