what is matter?
 Anything that has mass and takes up space.
who rejected Democritus idea about atoms?
Aristotle
what does Heisenberg Uncertainty Principle state?
It states that it is impossible to simultaneously know the exact position and momentum of an electron.
what is the arrangement of atoms in crystalline solids?
Atoms arranged in a highly ordered structure, forming a crystal lattice (e.g., salts, diamonds).
what are orbitals?
Regions in space where the probability of finding an electron is high
why are solids incompressible?
Particles arranged in fixed positions and in a regular pattern
describe the arrangement of particles in liquids?
Particles are close but not packed and  Particles can slide over each othe
describe the arrangement of particles in gasses?
Particles have a large gap between them
what happens in melting?
Solid becomes liquid.
what is deposition?
 Gas to solid without becoming liquid
what is sublimation?
Solid becomes gas without passing through the liquid phase.
what is density?
Density is the measure of how compact the mass in an object/substance is.
 Mass per unit volume
what is buoyancy?
Buoyancy is the upward force exerted by a fluid (liquid or gas) on an object immersed in it.
what does Archimedes principle state ?
Archimedes’ Principle states: "Any object completely or partially submerged in a fluid experiences an upward buoyant force equal to the weight of the fluid displaced by the object."
what are Van der waal’s forces?
Weak attractions between all atoms and molecules.
what are amorphous solids?
They lack a long-range order in atomic structure (e.g., glass, plastics).
state few mechanical properties of metals?
Strength, ductility, hardness, toughness.
state thermal properties of metals?
Conductivity, expansion.
state electrical properties of metals?
Conductivity, resistivity.
what are composite materials?
Combinations of two or more materials to enhance properties (e.g., fiberglass, concrete).
what does Heisenberg Uncertainty Principle state?
It States that it is impossible to simultaneously know the exact position and momentum of an electron.
what are dipole-dipole interactions?
Attractions between polar molecules.
what is hydrogen bonding?
Strong type of dipole-dipole interaction involving hydrogen and electronegative atoms like O, N, or F.
what are ionic bonds?
Transfer of electrons from one atom to another.
what are covalent bonds?
Sharing of electron pairs between atoms.
what are metallic bonds?
Delocalized electrons shared among metal atoms.
what is latent heat of vaporisation?
 Heat required to change a liquid to a gas.
what is temperature?
Measure of the average kinetic energy of particles.
what is latent heat of fusion?
 Heat required to change a solid to a liquid
what is latent heat?
Heat required for a phase change without a change in temperature