P6 Molecules And Matter Flashcards
What is the density of a substance defined as?
Substances mass per unit volume.
What is the equation for calculating the density of a substance?
Density, p (kilogram per cubic metre, kg/m3) = mass, m (kilograms, kg) ÷ volume, v (metres3, m**3).
What are examples of physical changes?
Solid.
Liquid.
Gas.
What are examples of the conservation of mass?
When given mass of ice melts, water it turns into has the same mass/ so mass of substance stays same.
When water boiled in kettle + some some of water turns into steam, the m ass of the steam produced is the same as the mass of water boiled away. So mass of substance is unchanged even though some of it (e.g., the steam) is no longer in the kettle.
What is the kinetic theory of matter?
If temperature of substance increased particles move faster.
What is the melting point of a substance?
Temperature at which the solid turns into a liquid.
What is the boiling point?
Temperature at which the liquid turns into a gas.
What is the freezing point?
Temperature at which the liquid turns into a solid.
What is condensation?
The liquid left on the cold surface from when a gas touched it.
What is latent heat?
Energy transferred to substance when changes its state.
What is fusion sometimes used to describe?
Melting as different solids can be joined or ‘fused’ together when they melt.
When does evaporation from a liquid happen?
At its surface when liquid below its boiling point. At its boiling point, liquid boils because of bubbles of vapour form inside liquid + rise to surface to release gas.
