General Chemistry 1 Exam 1 With 100% Correct Answers 2023

General Chemistry 1 Exam 1 With 100% Correct Answers 2023 Scientific Method 1) Identifying a question, developing a hypothesis 2) Perform experiment, make observations, record data 3) Interpret data, general hypothesis 4) Collect more data, maybe develop law or theory Law A statement that summarizes past observations and is used to predict future ones. Theory A possible explanation or a law Solid Fixed shape and volume Liquid Fixed volume, no fixed shape Gas No fixed volume or shape, Compressible. Homogeneous Mixture The composition of the mixture is the same throughout Heterogeneous Mixture The composition is not uniform Pure Substance A material that is composed of only one type of particle Mixtures A combination of two or more substances in which the substances retain their distinct identities Decanting To carefully pour off Filtration To separate using a physical boundary Distillation To separate via boiling point difference Physical Change Does not change composition Chemical Change Does change composition Celsius to Fahrenheit F=1.8C+32 Celsius to Kelvin K=C+273.15 Significant Figures: Multiplication/Division The total # of S.F in the answer is equal to the least # that appears in a measurement tera (T) 10^12 mega (M) 10^6 kilo (k) 10^3 deci (d) 10^-1 centi (c) 10^-2 milli (m) 10^-3 micro (μ) 10^-6 nano (n) 10^-9 pico (p) 10^-12 Derived Unit A unit derived from fundamental units of length, mass, and time. (1cm^3=1mL) Accuracy vs. Precision Random Error Error that is not repeatable and lead to fluctuations in results. Repetitions of the same experiment lead to different results. Systematic Error Error that is repeatable and means that the experimental measurements are centred on the wrong target J.J. Thomson Discovered the electron (cathode ray tube experiment) Robert Millikan Discovered the charge and mass of the electron (negative, 0.00055 amu) Via oil drop experiment Ernest Rutherford Discovered nuclear model of the atom via gold foil experiment. Atomic Theory Postulates -Matter is composed of very tiny or microscopic particles called "Atom". -Atom is an indivisible particle. -Atom can neither be created nor it is destroyed. -Atoms of an element are identical in size, shape, mass and in other properties. -Atoms of different elements are different in their properties. -Atoms combine with each other in small whole numbers. -All chemical reactions are due to combination or separation of atoms.