NES 103 Science STUDY Questions with Correct
Solutions
atom/molecule/compound
elements -> atom -> molecules (2+ same atoms) -> compounds (2+ different atoms)
periodic table (top number)
the top # called atomic number is the amount of protons
periodic table (bottom number)
called atomic mass, the sum of protons and neutrons
homogeneous mixture
What is a pure substance?
Only one type of atom or molecule (an element or compound).
What is a mixture?
Molecules/particles of two or more different materials mixed but not chemically combined.
homogeneous mixture
a mix with evenly distributed parts (dissolved salt water = 1 salt + 1 water); type is solution
heterogeneous mixture
not evenly distributed mix of substances
solutions
homogeneous mixture; two or more pure substances dissolves
, solutions parts
solute (dissolved material); solvent (main)
melting
solid to a liquid (gain energy)
vaporization
liquid to gas (boiling) (gain energy)
sublimation
solid straight to gas (gain energy)
condensation
gas to liquid (loose energy)
freezing
liquid to solid (loose energy)
deposition
gas strait to a solid (loose energy) (ex: frost)
phase change
when energy is added or removed, temperature remains constant until phase change complete
intensive properties
don't depend on substance amount but rather density, color, temperature
Solutions
atom/molecule/compound
elements -> atom -> molecules (2+ same atoms) -> compounds (2+ different atoms)
periodic table (top number)
the top # called atomic number is the amount of protons
periodic table (bottom number)
called atomic mass, the sum of protons and neutrons
homogeneous mixture
What is a pure substance?
Only one type of atom or molecule (an element or compound).
What is a mixture?
Molecules/particles of two or more different materials mixed but not chemically combined.
homogeneous mixture
a mix with evenly distributed parts (dissolved salt water = 1 salt + 1 water); type is solution
heterogeneous mixture
not evenly distributed mix of substances
solutions
homogeneous mixture; two or more pure substances dissolves
, solutions parts
solute (dissolved material); solvent (main)
melting
solid to a liquid (gain energy)
vaporization
liquid to gas (boiling) (gain energy)
sublimation
solid straight to gas (gain energy)
condensation
gas to liquid (loose energy)
freezing
liquid to solid (loose energy)
deposition
gas strait to a solid (loose energy) (ex: frost)
phase change
when energy is added or removed, temperature remains constant until phase change complete
intensive properties
don't depend on substance amount but rather density, color, temperature
