topic 1 key words Flashcards
What is the definition for atmosphere?
The thin layer of air surrounding the Earth.
What is the Bohr Model?
A model of the atom that suggested that negative electrons orbit a positive nucleus at set distances. it is the currently accepted model.
What is the definition for change in thermal energy?
The product of mass, specific heat capacity and temperature change of a substance.
What are chemical changes?
Changes to the chemical structure of a substance. Not reversable.
What is condensation?
The changing from vapour state to a liquid state, when a substance is cooled.
What is density?
The mass per unit volume of an object.
What are electrons?
A negatively charged constituent of the atom, they are found in different energy levels, around the nucleus.
What is a liquid?
A liquid or gas.
What is evaporation?
the changing from a liquid state to a vapour state, when a substance is heated.
What is freezing?
The changing from a liquid state to a solid state, when a substrate is cooled.
What is a gas?
A state of matter in which the particles are spread far apart and have high kinetic energies.
What is latent heat?
The energy required for a substance to change state.
What is a liquid?
A state of matter in which the particles are in contact, but can flow over each other.
What is melting?
The changing from a solid state to liquid state, when a substance is heated.
What is the nucleus?
The positively charged centre of an atom, containing protons and neutrons
What are neutrons?
A neutrally charged constituent of the nucleus.
What are pascals?
The unit of pressure, equal to a force of one Newton acting perpendicular to an area of one metre squared.
What are physical changes?
Changes to the physical properties of a substance which can be reversed.
What is pressure in a liquid column?
Equal to the product of the height of the column, the density of the liquid and the gravitational field strength.
What is pressure?
The force acting perpendicular to a surface, per unit area.
What is the pressure of a gas?
The perpendicular force per unit area acting on the surfaces of a container as a result of the gas particles colliding with it.
What are protons?
A positively charged constituent of the nucleus.
What is the Rutherford model?
A model of the atom that represented that atom as being mostly empty space, with a dense positive centre and negative charges scattered around it.
What is a solid?
A state of matter in which the particles are tightly packed together and can only vibrate about their fixed positions.
What is specific heat capacity?
The amount of energy needed to increase the temperature of one kg of a substance by 1C.
What is specific latent heat pf fusion?
the amount of energy needed to change the state of 1kg of a substance of a substance from solid state to liquid state, whilst held at constant temperature.
What is specific latent heat of vaporisation?
The amount of energy needed to change the state of 1 kg of a substance from liquid state to vapour state, whilst held at constant temperature.
What is sublimation?
The direct changing of a substance from a solid state to a vapour state, without passing through the liquid phase.
What is specific latent heat?
The amount of energy needed to change the state of 1kg of a substance, whilst held at constant temperature.
What is temperature?
A measure of the average kinetic energy of particle in a substance.
What is the Thomson model?
A rejected model of the atom that represented the atom as a ball of positive charge, c=with negative charges distributed throughout it. plum pudding model.
What is upthrust?
The upward force acting on an object in a fluid, due to it experiencing a greater pressure below it than above it. It is equal to the weight of the fluid displaced by the object.
What is weight?
The force acting on an object due to gravity.
