GED PHYSICAL SCIENCE QUESTIONS WITH CORRECT ANSWERS GRADED TO PASS

Atoms - Basic unit of matter Protons - Positively charged particles Electrons - Negatively charged particles Neutrons - the particles of the nucleus that have no charge Nucleus - A region that is located at the center of an atom and contains most of the atom's mass (protons and neutrons) Ions - Charged particles Isotopes - Atoms of the same element that have different numbers of neutrons. Molecule - A group of atoms bonded together Element - A pure substance made of only one kind of atom Compound - A substance made up of atoms of two or more different elements joined by chemical bonds Periodic table - A chart of the elements showing the repeating pattern of their properties Chemical properties - Characteristic that cannot be observed without altering the substance Physical properties - A characteristic of a pure substance that can be observed without changing it into another substance. Density - Mass / Volume States of matter - the physical forms of matter, which include solid, liquid, and gas Solids - particals that move very little are aranged in a tight, regular pattern Liquids - doesn't keep the same shape, keeps the same volume Gases - A state of matter, have no fixed shape and take on the shape of the space they're in Chemical formula - A combination of symbols that represents the elements in a compound. Chemical equations - A representation of a chemical reaction using symbols of the elements to indicate the amount of substance of each reactant and product. Conservation of mass - The principal stating that matter is not created or destroyed during a chemical reaction Balance an equation - is making an equation have the same number of the smae kind of element on each side of the equation Limiting reactant - the substance that controls the quantity of product that can form in a chemical reaction Synthesis reactions - Two or more small molecules combine to form a larger one. A+B = AB Decomposition reaction - a reaction in which a single compound breaks down to form two or more simpler substances Replacement reaction - A reaction where compounds are rearranged into different compounds. Solution - A homogeneous mixture of two or more substances Solute - A substance that is dissolved in a solution. Solvent - A liquid substance capable of dissolving other substances Aqueous solution - a solution in which water is the solvent Concentration - A measurement of how much solute exists within a certain volume of solvent Solubility - A measure of how much solute can dissolve in a given solvent at a given temperature. Saturation - The maximum concentration of a solution. Saturation depends on temperature, volume, and type of solvent Unsaturated - A solution that contains less than the maximum amount of dissolved solute in a concentration. Saturated - A solution that contains all of the solute it can hold at a given temperature is ___. Supersaturated - a solution that contains more solute than it can theoretically hold at a given temperature; excess solute precipitates if a seed crystal is added Dilute - A solution that has a low concentration of solute