química Flashcards
intensive matter property:
independent of amount
extensive matter property:
depends on amount
chemical matter property:
when a substance goes through a chemical reaction and transforms
physical matter property:
without changing chemical identity of a substance
in what does matter clasifícate in?
mixtures and pure substances
mixtures:
homogeneous and heterogeneous
pure substances:
elements and compounds
what’s an element?
some type of atoms but different from others
what’s a compound?
2 or more elements, different type of atoms
what’s a mixture?
combination of 2 or more compounds and elements
what are the states of matter?
solid, liquid, gas
what state of matter can be compressed?
gas
at states of matter flow?
liquid, gas
how does solid takes shape?
if you apply force
how does liquid take shape?
the bottom of the container
how does gas take shape?
takes the shape of the container
energy:
it cannot be created or eliminated, just transformed
energy of motion
kinetic energy
stored energy
potential energy
produced by chemical reactions
chemical energy
derived from an electricity circuit
electric energy
produced by temperature
thermal energy
who discovered the neutron?
Chadwick
electrons spin around the nucleus forming ellipses?
true/false
true
discovered the nucleus
rutherford
what charge does protons have?
positive
what charge does neutrons have?
neutral
what charge does electrons have?
negative
what’s the atomic number?
number of protons
mass number=
protons+neutrons
Hund’s rule:
electrons with spin +1/2 are arranged before the ones with -1/2
Aufbau principle:
electrons orbiting one or more atoms fill the lowest available energy levels before filling the highest
Pauli’s exclusion principle:
no 2 elements of an atom can have the same set of 4 quantum numbers
what’s an isotope?
it has the same number of protons but different number of neutrons
uses of radioactive isotopes:
medicine, modern industry
what did dobreiner discover?
trends in certain properties of elements
law of octaves:
newlands: any specific elect will have similar chemical properties with the each 8 following
what did Mendeleev do?
putted the elements he knew in a table with atomic weight and valences
properties of elements are a function of their atomic numbers:
periodic law
