P6- molecules and matter Flashcards
What is the formula for density?
mass over volume
What is the unit for density?
kg/m3
How do you measure the density of a liquid?
Volume- measuring cylinder
Mass- weighing scale
Density- formula
What happens to objects that have a lower density than the liquid they are submerged in?
They will float.
How many g/cm3 are in kg/m3?
1000.
What happens to the number of particles when a substance changes state and why is this?
It stays the same; the mass of the substance is the same before and after the change of state.
What do particles in a solid do?
Vibrate around a fixed position, meaning they have a fixed shape
What do particles in a liquid do?
They come in contact with one-another regularly-random
doesn’t have a fixed shape and it can therefore flow.
What do particles in a gas do?
far apart- moves randomly and much faster
density is much less
What state if matter has the least energy?
The solid state
What state of matter has the most energy?
gas
What is boiling
When a liquid becomes a gas when it reaches its boiling point.
what is evaporation
When a liquid becomes a gas when before it reaches its boiling point.
What can impurities do to a substance’s melting and boiling point?
Change them.
What is latent heat?
The energy that must be transferred to a substance, to change its state.
For a temperature against time graph, what does a flat line show?
The melting and boiling points of the substance in question
Does the temperature of the substance change when a change in state is happening?
No.
What is internal energy
It is the total kinetic energy and potential energy stores of the particles in a substance.
Why do particles, in a substance, have kinetic energy?
Due to their individual positions relative to each other
What happens when the temp. of a substance increases, in terms of internal energy and particles?
The energy increases of the particles, meaning that the internal energy increases.
What happens when the total kinetic energy- of the particles- increases?
The substance’s temperature increases
What happens to the potential energy, when a substance changes state?
The particle’s potential energy increases
For a solid, what type of force of attraction are there between the particles?
Strong ones.
What happens when a solid is heated in terms of particles
The particle’s energy stores increase, giving the particles more energy to vibrate more vigorously.
What are the forces of attraction like in a liquid?
They are weaker than in a solid