chem prep

• Activities in the field of chemistry measure proportions and reaction rates in order to understand unfamiliar substances and how they behave, or to create new compounds.
• Inorganic chemistry is the study of the remaining subset of compounds, while organic chemistry is the study of carbon-containing compounds.
• The steps for solving a numeric word problem are: Analyze, calculate, and evaluate.
• Iron (Fe) has 8 electrons in the 3d sublevel.
• The elements that contain f subshell valence electrons are Lanthanides (Lanthanum, La) and actinides (Actinium, Ac).
• Scientific law is a statement that describes a natural phenomenon or relationship that has been repeatedly observed and confirmed through experiments.
• The electronic configuration of Chlorine is 1s^2 2s^2 2p^6 3s^2 3p^5.
• A hypothesis is an assumption made before any research has been done, while a theory is a principle formed to explain the things already shown in data.
• The steps to the scientific method are: Observation, question, hypothesis, experiment, data analysis, conclusion.
• Theories are tested facts, they cannot be changed unless new evidence is compatible with the theory.
• After an experiment is repeated, the data is evaluated, as it becomes more accurate and refined.
• Water boils at a higher temperature than ethanol, therefore this can be classified as an observation.
• The three states of matter are: Solid, liquid, gas.
• Physical properties of matter include color, malleability, solubility, electrical conductivity, density, melting point, and boiling point.
• Physical properties of water include colorlessness, orderliness, polarity, excellent solvent, and high heat capacity.
• A mixture is a physical combination of two or more pure substances, with two types: Homogeneous Mixture and Heterogenous Mixture.
• A compound is a type of substance that is composed of two or more different elements chemically bonded together.
• When Fe combines with oxygen, Iron oxide is formed.
• Hydrogen-2 (deuterium), has one proton and one neutron in its nucleus.
• The number of significant figures in 2.5 kg is 2.
• The metric unit for volume is the liter (L), while the metric unit for mass is the gram (g).
• The smallest metric unit of length is millimeters, while the largest is kilometer.
• 10^-4, 10^-2, 10^-8 10^-2, 10^-2 is the smallest
• The charge on the nucleus of an atom is always positive.
• Rusting iron is a chemical change because two substances come together to create a new substance.
• To convert 40 hours per week to seconds, first convert hours to minutes by multiplying 60, then convert minutes to seconds by multiplying 60 again.
• Density is calculated by dividing Mass by Volume
• 25 km converted to centimeters is 25,000 cm.
• Dalton's atomic theory proposed that elements are made up of small, indivisible particles called atoms.
• Mili is one-thousandth (1/1000), Centi is one-hundredth (1/100), Deci is one-tenth (1/10).
• Accuracy refers to how close a measurement or result is to the true value, while precision refers to how close multiple measurements of the same quality are to each other.
• The rows on the periodic table are arranged in periods based on increasing atomic number.
• Group 1A contains the alkali metals groups.
• An atom is mostly empty space, based on Rutherford's experiment by testing different atom particles.
• When electrons enter the “p” orbitals they must have opposite spins.
• The noble gasses on the periodic table, Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), and Radon (Rn), are very stable and not reactive because their outer electron shells are full.
• Atoms of the same element can have different masses because of isotopes.
• The element having the same s and p configurations for principal energy level 3 as the element F has for its principal energy level 2 is Chlorine (Cl).
• The maximum number of electrons in energy level 1 is 2, in energy level 2 is 8, and in energy level 3 is 8.
• Rutherford’s atomic theory came from his gold foil experiment, which revealed that atoms possess small, densely packed, and positively charged electrons at their core while the majority of the atom is empty space.