C1 Flashcards
What are particles?
A particle is a tiny bit of matter
What is the particle model?
The particle model describes how particles are arranged and how they move in solids, liquids and gases
Arrangement of particles in a solid?
Regular
Movement of particles in a solid?
Vibrate about
Fixed positions
Main movements in a gas?
Move quickly in all directions
What is a chemical change?
A change that produces one or more new substances.
What is a physical change?
Happens when a substance changes state or shape, or breaks into pieces.
What are atoms?
The smallest particles that make up a substance
How to calculate the ratio of distance to diameter?
Distance between atoms
————————————-
Diameter of atom
What are the limitations of doing the particle model?
The force between particles
The size of particles
The space between particles
Describe the difference between a physical change and a chemical change?
When a physical change occurs , there are no new substances made. During a chemical change, the atoms rearrange themselves to form new products.
Describe the differences between liquid and solids in terms of the movement of particles?
Particles in liquids are constantly moving with a random motion, whereas particles in solids vibrate around fixed positions.
State the two subatomic particles which form the nucleus and use their charges to explain whether the overall change of the nucleus is positive , negative or neutral.
Neutrons and protons.
Neutrons have no charge and protons are positively charged, so the nucleus has an overall positive charge.
Explain how the movement of electrons determines the atomic radius of an atom?
Electrons move around the nucleus in electron shells.
These electron shells cover a lot of space
The volume of these shells determine the size of the atom , and si the atomic radius.
What does the atomic number of carbon-12 show?
The atomic number shows that carbon has 6 protons.
