Structure of an atom
What are the the three main parts of an atom?
Proton, neutron and electron
What are the three main types of radiation?
Alpha, Beta, Gamma
What is meant by 'radioactive half-life'?
The time it takes for half of a radioactive substance to decay.
What is an exothermic reaction?
A reaction that releases heat.
How do particles in a solid transmit energy?
In a solid, particles are closely packed and vibrate in fixed positions. Energy is transmitted as vibrations pass from one particle to the next.
What is the charge of a neutron?
neutral
Which type of radiation is the most dangerous to humans?
How does the half-life of a substance affect how dangerous it is?
Shorter half-lives mean more radiation is emitted in a shorter time, making it more dangerous.
How does an endothermic reaction differ from an exothermic one?
An endothermic reaction absorbs heat, while an exothermic reaction releases heat.
What is the particle theory of matter?
The particle theory of matter states that all matter is made up of tiny particles that are in constant motion. The particles have spaces between them, and their movement depends on the energy they possess.
What is the nucleus and what particle/s does it contain?
The nucleus is the centre of an atom and contains protons and neutrons
What can block alpha radiation from passing through?
A sheet of paper or skin
If a substance has a half-life of 5 years, how much of it remains after 5 years?
50%
Give an example of an exothermic reaction.
Combustion of fuels.
Why do liquids transmit energy faster than gases but slower than solids?
Liquids have particles that are less tightly packed than solids but closer than gases. This allows energy to transfer through collisions more efficiently than in gases but less efficiently than in solids.
How can you find the number of protons in an atom?
By looking at the atomic number
How can gamma radiation affect human cells?
It can damage or kill cells, potentially leading to cancer.
What would happen to the amount of a radioactive substance after two half-lives?
25% would remain.
What happens to the temperature during an endothermic reaction?
The temperature decreases.
What is conduction, and how does it relate to particle theory?
Conduction is the transfer of energy through a substance by direct contact of particles. According to particle theory, energy is passed from high-energy particles to neighbouring low-energy particles through vibrations and collisions.
What is the overall charge of an atom?
Neutral, because it has an equal number of protons and electrons
Why is gamma radiation considered the strongest type of radiation?
Because it has the highest energy and can penetrate most materials.
If a sample has a half-life of 10 years, what fraction of it remains after 20 years?
1/4 or 25%
What is a common example of an endothermic reaction in everyday life?
Photosynthesis.
Why are metals good conductors of energy?
Metals have free electrons that move easily through the lattice of positive ions, transferring energy quickly through collisions with other particles.