Flashcards in C1 Deck (23):
What is a particle?
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
How are solids arranged and how do their particles move?
Solids are arranged regularly, with a very close distance between particles, and vibration about fixed positions
How are liquids arranged and how do their particles move?
Liquids are randomly arranged, with a close distance between particles and particles moving around each other
How are gases arranged and how do their particles move?
Gases are randomly arranged, with a far distance between particles and particles move quickly in all directions
What are physical changes?
Physical changes are changes where no new substances are made, and the particles stay the same, just in different forms. Physical changes are easy to reverse
What are chemical changes?
Chemical changes are changes that produce one or more new substances, which are chemically bonded in different ways. These are very difficult or impossible to reverse.
What are the forces between particles?
Particles have electrostatic forces of attraction between positive and negative charges. The forces become weaker the further apart the particles are.
What are the limitations of the particle model?
The particle model doesn't take the forces between particles, the size of particles and the space between particles into account.
Describe the atom
Where is most of the atom's mass?
An atom is a positively charged nucleus surrounded by negatively charged electrons, with the nuclear radius much smaller than that of the atom and most of the mass inside the nucleus
What is the typical size of an atom?
What is atomic radius?
Half the atoms diameter
What is bond length?
The distance between the centres of two joined atoms
What is the relative mass and charge of a proton?
What is the relative mass and charge of a neutron?
What is the relative mass and charge of an electron?
How do you calculate the number of protons in an atom or ion?
The number of protons is the atoms atomic number
How do you calculate the number of neutrons in an atom or ion?
The number of neutrons is the
mass number - atomic number
How do you calculate the number of electrons in an atom or ion?
For an atom, it is equal to the number of protons (atomic number)
For an ion, it is the atomic number - charge on ion
a charged particle, formed when atoms, or groups of atoms gain or lose electrons
the number of protons in an atoms nucleus
the total number of protons and neutrons in an atom