CHEMISTRY D425 (WGU OA KEY POINTS
UPDATED 2024) QUESTIONS WITH
COMPLETE SOLUTIONS!!
How is matter classified? Answer - pure substances and mixtures Avogadro's number Answer - number of representative particles in a mole,
6.02 X 10^23
Words like atom, particles, molecules, formula units mean? Answer - use Avogadro's number 6.02x10^23 Imperial System Answer - the system of measurement used in the United States What is an element? Answer - A substance that cannot be broken down into simpler substances What is an compound? Answer - pure substance that contains more than one element and can be broken down into chemically simpler components What is a mixture? Answer - 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? Answer - solid, liquid, gas 1 / 2
What is matter composed of? Answer - atoms How is energy transferred? Answer - heat and work What is the motion of energy? Answer - kinetic energy what is resting energy? Answer - potential energy What is a molecule ? Answer - a group of two or more atoms held together by chemical bonds Is matter affected by physical changes? Answer - physical changes DO NOT alter the composition of matter Is matter affected by chemical changes ? Answer - Chemical changes transform matter in such a way that the identity or chemical substance changes matter can neither be created nor destroyed Answer - What is the law of conservation of mass?bonding electron pair Answer - two electrons shared between atoms What are core electrons? Answer - inner electrons core shell What are colvalent bonds? Answer - bond formed by the sharing of electrons between nonmetals
example: H2O, NH3
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