Chemistry D425 exam with
answers
How is matter classified?
pure substances and mixtures
Avogadro's number
number of representative particles in a mole, 6.02 X 10^23
Words like atom, particles, molecules, formula units mean?
use Avogadro's number 6.02x10^23
Imperial System
the system of measurement used in the United States
What is an element?
A substance that cannot be broken down into simpler substances
What is an compound?
pure substance that contains more than one element and can be
broken down into chemically simpler components
What is a mixture?
is a physical blend of two or more pure substances where each
retains its own identity and properties in the mixture
What are the three phases of matter?
solid, liquid, gas
What is matter composed of?
, atoms
How is energy transferred?
heat and work
What is the motion of energy?
kinetic energy
what is resting energy?
potential energy
What is a molecule ?
a group of two or more atoms held together by chemical bonds
Is matter affected by physical changes?
physical changes DO NOT alter the composition of matter
Is matter affected by chemical changes ?
Chemical changes transform matter in such a way that the identity or
chemical substance changes
matter can neither be created nor destroyed
What is the law of conservation of mass?
bonding electron pair
two electrons shared between atoms
What are core electrons?
inner electrons core shell
What are colvalent bonds?
answers
How is matter classified?
pure substances and mixtures
Avogadro's number
number of representative particles in a mole, 6.02 X 10^23
Words like atom, particles, molecules, formula units mean?
use Avogadro's number 6.02x10^23
Imperial System
the system of measurement used in the United States
What is an element?
A substance that cannot be broken down into simpler substances
What is an compound?
pure substance that contains more than one element and can be
broken down into chemically simpler components
What is a mixture?
is a physical blend of two or more pure substances where each
retains its own identity and properties in the mixture
What are the three phases of matter?
solid, liquid, gas
What is matter composed of?
, atoms
How is energy transferred?
heat and work
What is the motion of energy?
kinetic energy
what is resting energy?
potential energy
What is a molecule ?
a group of two or more atoms held together by chemical bonds
Is matter affected by physical changes?
physical changes DO NOT alter the composition of matter
Is matter affected by chemical changes ?
Chemical changes transform matter in such a way that the identity or
chemical substance changes
matter can neither be created nor destroyed
What is the law of conservation of mass?
bonding electron pair
two electrons shared between atoms
What are core electrons?
inner electrons core shell
What are colvalent bonds?
