P4- Atomic Structure Flashcards
What is an atom?
An atom is the smallest part of any substance. All substances are made up of atoms.
What is an isotope?
The same element with the same number of protons but different number of neutrons.
Why are atoms electrically neutral charge?
Atoms have the same number of positive protons and negative electrons.
Describe the nuclear model.
Mainly empty space with a tiny nucleus where the mass is concentrated. The positive charge is in the nucleus and the electrons orbit the nucleus.
Describe the plum pudding model.
A positively charged solid sphere with electrons scattered throughout.
What instrument do we use to measure radiation?
Geiger-Müller tube or counter.
What is radiation?
Radiation is when in large unstable nucleus emits particles and energy to become stable.
What does an alpha particle consist of?
Two protons and two neutrons.
What does a beta particle consist of?
A fast–moving electron.
How is gamma radiation different to alpha and beta radiation?
Alpha and Beta radiation involve particles. Gamma radiation travels in waves and does not involve any particles
Why is ionisation harmful?
It can cause mutations in our cells which may lead to cancers.
How are every irradiation and contamination different?
Radiation is exposure to radiation from a radioactive source.
Contamination is where unwanted atoms of a radioactive substance are present on or inside another material.
What is the definition of half-life?
The time taken for the unstable nuclei to decay or the activity of the sample to halve or for the count rate to halve.
